1 /* GNU/Linux native-dependent code common to multiple platforms.
3 Copyright (C) 2001-2016 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "nat/linux-nat.h"
25 #include "nat/linux-waitpid.h"
28 #include <sys/syscall.h>
29 #include "nat/gdb_ptrace.h"
30 #include "linux-nat.h"
31 #include "nat/linux-ptrace.h"
32 #include "nat/linux-procfs.h"
33 #include "nat/linux-personality.h"
34 #include "linux-fork.h"
35 #include "gdbthread.h"
39 #include "inf-child.h"
40 #include "inf-ptrace.h"
42 #include <sys/procfs.h> /* for elf_gregset etc. */
43 #include "elf-bfd.h" /* for elfcore_write_* */
44 #include "gregset.h" /* for gregset */
45 #include "gdbcore.h" /* for get_exec_file */
46 #include <ctype.h> /* for isdigit */
47 #include <sys/stat.h> /* for struct stat */
48 #include <fcntl.h> /* for O_RDONLY */
50 #include "event-loop.h"
51 #include "event-top.h"
53 #include <sys/types.h>
55 #include "xml-support.h"
58 #include "nat/linux-osdata.h"
59 #include "linux-tdep.h"
62 #include "tracepoint.h"
64 #include "target-descriptions.h"
65 #include "filestuff.h"
67 #include "nat/linux-namespaces.h"
71 #define SPUFS_MAGIC 0x23c9b64e
74 /* This comment documents high-level logic of this file.
76 Waiting for events in sync mode
77 ===============================
79 When waiting for an event in a specific thread, we just use waitpid,
80 passing the specific pid, and not passing WNOHANG.
82 When waiting for an event in all threads, waitpid is not quite good:
84 - If the thread group leader exits while other threads in the thread
85 group still exist, waitpid(TGID, ...) hangs. That waitpid won't
86 return an exit status until the other threads in the group are
89 - When a non-leader thread execs, that thread just vanishes without
90 reporting an exit (so we'd hang if we waited for it explicitly in
91 that case). The exec event is instead reported to the TGID pid.
93 The solution is to always use -1 and WNOHANG, together with
96 First, we use non-blocking waitpid to check for events. If nothing is
97 found, we use sigsuspend to wait for SIGCHLD. When SIGCHLD arrives,
98 it means something happened to a child process. As soon as we know
99 there's an event, we get back to calling nonblocking waitpid.
101 Note that SIGCHLD should be blocked between waitpid and sigsuspend
102 calls, so that we don't miss a signal. If SIGCHLD arrives in between,
103 when it's blocked, the signal becomes pending and sigsuspend
104 immediately notices it and returns.
106 Waiting for events in async mode (TARGET_WNOHANG)
107 =================================================
109 In async mode, GDB should always be ready to handle both user input
110 and target events, so neither blocking waitpid nor sigsuspend are
111 viable options. Instead, we should asynchronously notify the GDB main
112 event loop whenever there's an unprocessed event from the target. We
113 detect asynchronous target events by handling SIGCHLD signals. To
114 notify the event loop about target events, the self-pipe trick is used
115 --- a pipe is registered as waitable event source in the event loop,
116 the event loop select/poll's on the read end of this pipe (as well on
117 other event sources, e.g., stdin), and the SIGCHLD handler writes a
118 byte to this pipe. This is more portable than relying on
119 pselect/ppoll, since on kernels that lack those syscalls, libc
120 emulates them with select/poll+sigprocmask, and that is racy
121 (a.k.a. plain broken).
123 Obviously, if we fail to notify the event loop if there's a target
124 event, it's bad. OTOH, if we notify the event loop when there's no
125 event from the target, linux_nat_wait will detect that there's no real
126 event to report, and return event of type TARGET_WAITKIND_IGNORE.
127 This is mostly harmless, but it will waste time and is better avoided.
129 The main design point is that every time GDB is outside linux-nat.c,
130 we have a SIGCHLD handler installed that is called when something
131 happens to the target and notifies the GDB event loop. Whenever GDB
132 core decides to handle the event, and calls into linux-nat.c, we
133 process things as in sync mode, except that the we never block in
136 While processing an event, we may end up momentarily blocked in
137 waitpid calls. Those waitpid calls, while blocking, are guarantied to
138 return quickly. E.g., in all-stop mode, before reporting to the core
139 that an LWP hit a breakpoint, all LWPs are stopped by sending them
140 SIGSTOP, and synchronously waiting for the SIGSTOP to be reported.
141 Note that this is different from blocking indefinitely waiting for the
142 next event --- here, we're already handling an event.
147 We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another
148 signal is not entirely significant; we just need for a signal to be delivered,
149 so that we can intercept it. SIGSTOP's advantage is that it can not be
150 blocked. A disadvantage is that it is not a real-time signal, so it can only
151 be queued once; we do not keep track of other sources of SIGSTOP.
153 Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't
154 use them, because they have special behavior when the signal is generated -
155 not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL
156 kills the entire thread group.
158 A delivered SIGSTOP would stop the entire thread group, not just the thread we
159 tkill'd. But we never let the SIGSTOP be delivered; we always intercept and
160 cancel it (by PTRACE_CONT without passing SIGSTOP).
162 We could use a real-time signal instead. This would solve those problems; we
163 could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB.
164 But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH
165 generates it, and there are races with trying to find a signal that is not
171 The case of a thread group (process) with 3 or more threads, and a
172 thread other than the leader execs is worth detailing:
174 On an exec, the Linux kernel destroys all threads except the execing
175 one in the thread group, and resets the execing thread's tid to the
176 tgid. No exit notification is sent for the execing thread -- from the
177 ptracer's perspective, it appears as though the execing thread just
178 vanishes. Until we reap all other threads except the leader and the
179 execing thread, the leader will be zombie, and the execing thread will
180 be in `D (disc sleep)' state. As soon as all other threads are
181 reaped, the execing thread changes its tid to the tgid, and the
182 previous (zombie) leader vanishes, giving place to the "new"
186 #define O_LARGEFILE 0
189 /* Does the current host support PTRACE_GETREGSET? */
190 enum tribool have_ptrace_getregset
= TRIBOOL_UNKNOWN
;
192 /* The single-threaded native GNU/Linux target_ops. We save a pointer for
193 the use of the multi-threaded target. */
194 static struct target_ops
*linux_ops
;
195 static struct target_ops linux_ops_saved
;
197 /* The method to call, if any, when a new thread is attached. */
198 static void (*linux_nat_new_thread
) (struct lwp_info
*);
200 /* The method to call, if any, when a new fork is attached. */
201 static linux_nat_new_fork_ftype
*linux_nat_new_fork
;
203 /* The method to call, if any, when a process is no longer
205 static linux_nat_forget_process_ftype
*linux_nat_forget_process_hook
;
207 /* Hook to call prior to resuming a thread. */
208 static void (*linux_nat_prepare_to_resume
) (struct lwp_info
*);
210 /* The method to call, if any, when the siginfo object needs to be
211 converted between the layout returned by ptrace, and the layout in
212 the architecture of the inferior. */
213 static int (*linux_nat_siginfo_fixup
) (siginfo_t
*,
217 /* The saved to_xfer_partial method, inherited from inf-ptrace.c.
218 Called by our to_xfer_partial. */
219 static target_xfer_partial_ftype
*super_xfer_partial
;
221 /* The saved to_close method, inherited from inf-ptrace.c.
222 Called by our to_close. */
223 static void (*super_close
) (struct target_ops
*);
225 static unsigned int debug_linux_nat
;
227 show_debug_linux_nat (struct ui_file
*file
, int from_tty
,
228 struct cmd_list_element
*c
, const char *value
)
230 fprintf_filtered (file
, _("Debugging of GNU/Linux lwp module is %s.\n"),
234 struct simple_pid_list
238 struct simple_pid_list
*next
;
240 struct simple_pid_list
*stopped_pids
;
242 /* Whether target_thread_events is in effect. */
243 static int report_thread_events
;
245 /* Async mode support. */
247 /* The read/write ends of the pipe registered as waitable file in the
249 static int linux_nat_event_pipe
[2] = { -1, -1 };
251 /* True if we're currently in async mode. */
252 #define linux_is_async_p() (linux_nat_event_pipe[0] != -1)
254 /* Flush the event pipe. */
257 async_file_flush (void)
264 ret
= read (linux_nat_event_pipe
[0], &buf
, 1);
266 while (ret
>= 0 || (ret
== -1 && errno
== EINTR
));
269 /* Put something (anything, doesn't matter what, or how much) in event
270 pipe, so that the select/poll in the event-loop realizes we have
271 something to process. */
274 async_file_mark (void)
278 /* It doesn't really matter what the pipe contains, as long we end
279 up with something in it. Might as well flush the previous
285 ret
= write (linux_nat_event_pipe
[1], "+", 1);
287 while (ret
== -1 && errno
== EINTR
);
289 /* Ignore EAGAIN. If the pipe is full, the event loop will already
290 be awakened anyway. */
293 static int kill_lwp (int lwpid
, int signo
);
295 static int stop_callback (struct lwp_info
*lp
, void *data
);
296 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
298 static void block_child_signals (sigset_t
*prev_mask
);
299 static void restore_child_signals_mask (sigset_t
*prev_mask
);
302 static struct lwp_info
*add_lwp (ptid_t ptid
);
303 static void purge_lwp_list (int pid
);
304 static void delete_lwp (ptid_t ptid
);
305 static struct lwp_info
*find_lwp_pid (ptid_t ptid
);
307 static int lwp_status_pending_p (struct lwp_info
*lp
);
309 static int sigtrap_is_event (int status
);
310 static int (*linux_nat_status_is_event
) (int status
) = sigtrap_is_event
;
312 static void save_stop_reason (struct lwp_info
*lp
);
317 /* See nat/linux-nat.h. */
320 ptid_of_lwp (struct lwp_info
*lwp
)
325 /* See nat/linux-nat.h. */
328 lwp_set_arch_private_info (struct lwp_info
*lwp
,
329 struct arch_lwp_info
*info
)
331 lwp
->arch_private
= info
;
334 /* See nat/linux-nat.h. */
336 struct arch_lwp_info
*
337 lwp_arch_private_info (struct lwp_info
*lwp
)
339 return lwp
->arch_private
;
342 /* See nat/linux-nat.h. */
345 lwp_is_stopped (struct lwp_info
*lwp
)
350 /* See nat/linux-nat.h. */
352 enum target_stop_reason
353 lwp_stop_reason (struct lwp_info
*lwp
)
355 return lwp
->stop_reason
;
359 /* Trivial list manipulation functions to keep track of a list of
360 new stopped processes. */
362 add_to_pid_list (struct simple_pid_list
**listp
, int pid
, int status
)
364 struct simple_pid_list
*new_pid
= XNEW (struct simple_pid_list
);
367 new_pid
->status
= status
;
368 new_pid
->next
= *listp
;
373 pull_pid_from_list (struct simple_pid_list
**listp
, int pid
, int *statusp
)
375 struct simple_pid_list
**p
;
377 for (p
= listp
; *p
!= NULL
; p
= &(*p
)->next
)
378 if ((*p
)->pid
== pid
)
380 struct simple_pid_list
*next
= (*p
)->next
;
382 *statusp
= (*p
)->status
;
390 /* Return the ptrace options that we want to try to enable. */
393 linux_nat_ptrace_options (int attached
)
398 options
|= PTRACE_O_EXITKILL
;
400 options
|= (PTRACE_O_TRACESYSGOOD
401 | PTRACE_O_TRACEVFORKDONE
402 | PTRACE_O_TRACEVFORK
404 | PTRACE_O_TRACEEXEC
);
409 /* Initialize ptrace warnings and check for supported ptrace
412 ATTACHED should be nonzero iff we attached to the inferior. */
415 linux_init_ptrace (pid_t pid
, int attached
)
417 int options
= linux_nat_ptrace_options (attached
);
419 linux_enable_event_reporting (pid
, options
);
420 linux_ptrace_init_warnings ();
424 linux_child_post_attach (struct target_ops
*self
, int pid
)
426 linux_init_ptrace (pid
, 1);
430 linux_child_post_startup_inferior (struct target_ops
*self
, ptid_t ptid
)
432 linux_init_ptrace (ptid_get_pid (ptid
), 0);
435 /* Return the number of known LWPs in the tgid given by PID. */
443 for (lp
= lwp_list
; lp
; lp
= lp
->next
)
444 if (ptid_get_pid (lp
->ptid
) == pid
)
450 /* Call delete_lwp with prototype compatible for make_cleanup. */
453 delete_lwp_cleanup (void *lp_voidp
)
455 struct lwp_info
*lp
= (struct lwp_info
*) lp_voidp
;
457 delete_lwp (lp
->ptid
);
460 /* Target hook for follow_fork. On entry inferior_ptid must be the
461 ptid of the followed inferior. At return, inferior_ptid will be
465 linux_child_follow_fork (struct target_ops
*ops
, int follow_child
,
470 struct lwp_info
*child_lp
= NULL
;
471 int status
= W_STOPCODE (0);
472 struct cleanup
*old_chain
;
474 ptid_t parent_ptid
, child_ptid
;
475 int parent_pid
, child_pid
;
477 has_vforked
= (inferior_thread ()->pending_follow
.kind
478 == TARGET_WAITKIND_VFORKED
);
479 parent_ptid
= inferior_ptid
;
480 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
481 parent_pid
= ptid_get_lwp (parent_ptid
);
482 child_pid
= ptid_get_lwp (child_ptid
);
484 /* We're already attached to the parent, by default. */
485 old_chain
= save_inferior_ptid ();
486 inferior_ptid
= child_ptid
;
487 child_lp
= add_lwp (inferior_ptid
);
488 child_lp
->stopped
= 1;
489 child_lp
->last_resume_kind
= resume_stop
;
491 /* Detach new forked process? */
494 make_cleanup (delete_lwp_cleanup
, child_lp
);
496 if (linux_nat_prepare_to_resume
!= NULL
)
497 linux_nat_prepare_to_resume (child_lp
);
499 /* When debugging an inferior in an architecture that supports
500 hardware single stepping on a kernel without commit
501 6580807da14c423f0d0a708108e6df6ebc8bc83d, the vfork child
502 process starts with the TIF_SINGLESTEP/X86_EFLAGS_TF bits
503 set if the parent process had them set.
504 To work around this, single step the child process
505 once before detaching to clear the flags. */
507 if (!gdbarch_software_single_step_p (target_thread_architecture
510 linux_disable_event_reporting (child_pid
);
511 if (ptrace (PTRACE_SINGLESTEP
, child_pid
, 0, 0) < 0)
512 perror_with_name (_("Couldn't do single step"));
513 if (my_waitpid (child_pid
, &status
, 0) < 0)
514 perror_with_name (_("Couldn't wait vfork process"));
517 if (WIFSTOPPED (status
))
521 signo
= WSTOPSIG (status
);
523 && !signal_pass_state (gdb_signal_from_host (signo
)))
525 ptrace (PTRACE_DETACH
, child_pid
, 0, signo
);
528 /* Resets value of inferior_ptid to parent ptid. */
529 do_cleanups (old_chain
);
533 /* Let the thread_db layer learn about this new process. */
534 check_for_thread_db ();
537 do_cleanups (old_chain
);
541 struct lwp_info
*parent_lp
;
543 parent_lp
= find_lwp_pid (parent_ptid
);
544 gdb_assert (linux_supports_tracefork () >= 0);
546 if (linux_supports_tracevforkdone ())
549 fprintf_unfiltered (gdb_stdlog
,
550 "LCFF: waiting for VFORK_DONE on %d\n",
552 parent_lp
->stopped
= 1;
554 /* We'll handle the VFORK_DONE event like any other
555 event, in target_wait. */
559 /* We can't insert breakpoints until the child has
560 finished with the shared memory region. We need to
561 wait until that happens. Ideal would be to just
563 - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0);
564 - waitpid (parent_pid, &status, __WALL);
565 However, most architectures can't handle a syscall
566 being traced on the way out if it wasn't traced on
569 We might also think to loop, continuing the child
570 until it exits or gets a SIGTRAP. One problem is
571 that the child might call ptrace with PTRACE_TRACEME.
573 There's no simple and reliable way to figure out when
574 the vforked child will be done with its copy of the
575 shared memory. We could step it out of the syscall,
576 two instructions, let it go, and then single-step the
577 parent once. When we have hardware single-step, this
578 would work; with software single-step it could still
579 be made to work but we'd have to be able to insert
580 single-step breakpoints in the child, and we'd have
581 to insert -just- the single-step breakpoint in the
582 parent. Very awkward.
584 In the end, the best we can do is to make sure it
585 runs for a little while. Hopefully it will be out of
586 range of any breakpoints we reinsert. Usually this
587 is only the single-step breakpoint at vfork's return
591 fprintf_unfiltered (gdb_stdlog
,
592 "LCFF: no VFORK_DONE "
593 "support, sleeping a bit\n");
597 /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event,
598 and leave it pending. The next linux_nat_resume call
599 will notice a pending event, and bypasses actually
600 resuming the inferior. */
601 parent_lp
->status
= 0;
602 parent_lp
->waitstatus
.kind
= TARGET_WAITKIND_VFORK_DONE
;
603 parent_lp
->stopped
= 1;
605 /* If we're in async mode, need to tell the event loop
606 there's something here to process. */
607 if (target_is_async_p ())
614 struct lwp_info
*child_lp
;
616 child_lp
= add_lwp (inferior_ptid
);
617 child_lp
->stopped
= 1;
618 child_lp
->last_resume_kind
= resume_stop
;
620 /* Let the thread_db layer learn about this new process. */
621 check_for_thread_db ();
629 linux_child_insert_fork_catchpoint (struct target_ops
*self
, int pid
)
631 return !linux_supports_tracefork ();
635 linux_child_remove_fork_catchpoint (struct target_ops
*self
, int pid
)
641 linux_child_insert_vfork_catchpoint (struct target_ops
*self
, int pid
)
643 return !linux_supports_tracefork ();
647 linux_child_remove_vfork_catchpoint (struct target_ops
*self
, int pid
)
653 linux_child_insert_exec_catchpoint (struct target_ops
*self
, int pid
)
655 return !linux_supports_tracefork ();
659 linux_child_remove_exec_catchpoint (struct target_ops
*self
, int pid
)
665 linux_child_set_syscall_catchpoint (struct target_ops
*self
,
666 int pid
, int needed
, int any_count
,
667 int table_size
, int *table
)
669 if (!linux_supports_tracesysgood ())
672 /* On GNU/Linux, we ignore the arguments. It means that we only
673 enable the syscall catchpoints, but do not disable them.
675 Also, we do not use the `table' information because we do not
676 filter system calls here. We let GDB do the logic for us. */
680 /* List of known LWPs, keyed by LWP PID. This speeds up the common
681 case of mapping a PID returned from the kernel to our corresponding
682 lwp_info data structure. */
683 static htab_t lwp_lwpid_htab
;
685 /* Calculate a hash from a lwp_info's LWP PID. */
688 lwp_info_hash (const void *ap
)
690 const struct lwp_info
*lp
= (struct lwp_info
*) ap
;
691 pid_t pid
= ptid_get_lwp (lp
->ptid
);
693 return iterative_hash_object (pid
, 0);
696 /* Equality function for the lwp_info hash table. Compares the LWP's
700 lwp_lwpid_htab_eq (const void *a
, const void *b
)
702 const struct lwp_info
*entry
= (const struct lwp_info
*) a
;
703 const struct lwp_info
*element
= (const struct lwp_info
*) b
;
705 return ptid_get_lwp (entry
->ptid
) == ptid_get_lwp (element
->ptid
);
708 /* Create the lwp_lwpid_htab hash table. */
711 lwp_lwpid_htab_create (void)
713 lwp_lwpid_htab
= htab_create (100, lwp_info_hash
, lwp_lwpid_htab_eq
, NULL
);
716 /* Add LP to the hash table. */
719 lwp_lwpid_htab_add_lwp (struct lwp_info
*lp
)
723 slot
= htab_find_slot (lwp_lwpid_htab
, lp
, INSERT
);
724 gdb_assert (slot
!= NULL
&& *slot
== NULL
);
728 /* Head of doubly-linked list of known LWPs. Sorted by reverse
729 creation order. This order is assumed in some cases. E.g.,
730 reaping status after killing alls lwps of a process: the leader LWP
731 must be reaped last. */
732 struct lwp_info
*lwp_list
;
734 /* Add LP to sorted-by-reverse-creation-order doubly-linked list. */
737 lwp_list_add (struct lwp_info
*lp
)
740 if (lwp_list
!= NULL
)
745 /* Remove LP from sorted-by-reverse-creation-order doubly-linked
749 lwp_list_remove (struct lwp_info
*lp
)
751 /* Remove from sorted-by-creation-order list. */
752 if (lp
->next
!= NULL
)
753 lp
->next
->prev
= lp
->prev
;
754 if (lp
->prev
!= NULL
)
755 lp
->prev
->next
= lp
->next
;
762 /* Original signal mask. */
763 static sigset_t normal_mask
;
765 /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in
766 _initialize_linux_nat. */
767 static sigset_t suspend_mask
;
769 /* Signals to block to make that sigsuspend work. */
770 static sigset_t blocked_mask
;
772 /* SIGCHLD action. */
773 struct sigaction sigchld_action
;
775 /* Block child signals (SIGCHLD and linux threads signals), and store
776 the previous mask in PREV_MASK. */
779 block_child_signals (sigset_t
*prev_mask
)
781 /* Make sure SIGCHLD is blocked. */
782 if (!sigismember (&blocked_mask
, SIGCHLD
))
783 sigaddset (&blocked_mask
, SIGCHLD
);
785 sigprocmask (SIG_BLOCK
, &blocked_mask
, prev_mask
);
788 /* Restore child signals mask, previously returned by
789 block_child_signals. */
792 restore_child_signals_mask (sigset_t
*prev_mask
)
794 sigprocmask (SIG_SETMASK
, prev_mask
, NULL
);
797 /* Mask of signals to pass directly to the inferior. */
798 static sigset_t pass_mask
;
800 /* Update signals to pass to the inferior. */
802 linux_nat_pass_signals (struct target_ops
*self
,
803 int numsigs
, unsigned char *pass_signals
)
807 sigemptyset (&pass_mask
);
809 for (signo
= 1; signo
< NSIG
; signo
++)
811 int target_signo
= gdb_signal_from_host (signo
);
812 if (target_signo
< numsigs
&& pass_signals
[target_signo
])
813 sigaddset (&pass_mask
, signo
);
819 /* Prototypes for local functions. */
820 static int stop_wait_callback (struct lwp_info
*lp
, void *data
);
821 static char *linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
);
822 static int resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
);
826 /* Destroy and free LP. */
829 lwp_free (struct lwp_info
*lp
)
831 xfree (lp
->arch_private
);
835 /* Traversal function for purge_lwp_list. */
838 lwp_lwpid_htab_remove_pid (void **slot
, void *info
)
840 struct lwp_info
*lp
= (struct lwp_info
*) *slot
;
841 int pid
= *(int *) info
;
843 if (ptid_get_pid (lp
->ptid
) == pid
)
845 htab_clear_slot (lwp_lwpid_htab
, slot
);
846 lwp_list_remove (lp
);
853 /* Remove all LWPs belong to PID from the lwp list. */
856 purge_lwp_list (int pid
)
858 htab_traverse_noresize (lwp_lwpid_htab
, lwp_lwpid_htab_remove_pid
, &pid
);
861 /* Add the LWP specified by PTID to the list. PTID is the first LWP
862 in the process. Return a pointer to the structure describing the
865 This differs from add_lwp in that we don't let the arch specific
866 bits know about this new thread. Current clients of this callback
867 take the opportunity to install watchpoints in the new thread, and
868 we shouldn't do that for the first thread. If we're spawning a
869 child ("run"), the thread executes the shell wrapper first, and we
870 shouldn't touch it until it execs the program we want to debug.
871 For "attach", it'd be okay to call the callback, but it's not
872 necessary, because watchpoints can't yet have been inserted into
875 static struct lwp_info
*
876 add_initial_lwp (ptid_t ptid
)
880 gdb_assert (ptid_lwp_p (ptid
));
882 lp
= XNEW (struct lwp_info
);
884 memset (lp
, 0, sizeof (struct lwp_info
));
886 lp
->last_resume_kind
= resume_continue
;
887 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
892 /* Add to sorted-by-reverse-creation-order list. */
895 /* Add to keyed-by-pid htab. */
896 lwp_lwpid_htab_add_lwp (lp
);
901 /* Add the LWP specified by PID to the list. Return a pointer to the
902 structure describing the new LWP. The LWP should already be
905 static struct lwp_info
*
906 add_lwp (ptid_t ptid
)
910 lp
= add_initial_lwp (ptid
);
912 /* Let the arch specific bits know about this new thread. Current
913 clients of this callback take the opportunity to install
914 watchpoints in the new thread. We don't do this for the first
915 thread though. See add_initial_lwp. */
916 if (linux_nat_new_thread
!= NULL
)
917 linux_nat_new_thread (lp
);
922 /* Remove the LWP specified by PID from the list. */
925 delete_lwp (ptid_t ptid
)
929 struct lwp_info dummy
;
932 slot
= htab_find_slot (lwp_lwpid_htab
, &dummy
, NO_INSERT
);
936 lp
= *(struct lwp_info
**) slot
;
937 gdb_assert (lp
!= NULL
);
939 htab_clear_slot (lwp_lwpid_htab
, slot
);
941 /* Remove from sorted-by-creation-order list. */
942 lwp_list_remove (lp
);
948 /* Return a pointer to the structure describing the LWP corresponding
949 to PID. If no corresponding LWP could be found, return NULL. */
951 static struct lwp_info
*
952 find_lwp_pid (ptid_t ptid
)
956 struct lwp_info dummy
;
958 if (ptid_lwp_p (ptid
))
959 lwp
= ptid_get_lwp (ptid
);
961 lwp
= ptid_get_pid (ptid
);
963 dummy
.ptid
= ptid_build (0, lwp
, 0);
964 lp
= (struct lwp_info
*) htab_find (lwp_lwpid_htab
, &dummy
);
968 /* See nat/linux-nat.h. */
971 iterate_over_lwps (ptid_t filter
,
972 iterate_over_lwps_ftype callback
,
975 struct lwp_info
*lp
, *lpnext
;
977 for (lp
= lwp_list
; lp
; lp
= lpnext
)
981 if (ptid_match (lp
->ptid
, filter
))
983 if ((*callback
) (lp
, data
) != 0)
991 /* Update our internal state when changing from one checkpoint to
992 another indicated by NEW_PTID. We can only switch single-threaded
993 applications, so we only create one new LWP, and the previous list
997 linux_nat_switch_fork (ptid_t new_ptid
)
1001 purge_lwp_list (ptid_get_pid (inferior_ptid
));
1003 lp
= add_lwp (new_ptid
);
1006 /* This changes the thread's ptid while preserving the gdb thread
1007 num. Also changes the inferior pid, while preserving the
1009 thread_change_ptid (inferior_ptid
, new_ptid
);
1011 /* We've just told GDB core that the thread changed target id, but,
1012 in fact, it really is a different thread, with different register
1014 registers_changed ();
1017 /* Handle the exit of a single thread LP. */
1020 exit_lwp (struct lwp_info
*lp
)
1022 struct thread_info
*th
= find_thread_ptid (lp
->ptid
);
1026 if (print_thread_events
)
1027 printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp
->ptid
));
1029 delete_thread (lp
->ptid
);
1032 delete_lwp (lp
->ptid
);
1035 /* Wait for the LWP specified by LP, which we have just attached to.
1036 Returns a wait status for that LWP, to cache. */
1039 linux_nat_post_attach_wait (ptid_t ptid
, int first
, int *signalled
)
1041 pid_t new_pid
, pid
= ptid_get_lwp (ptid
);
1044 if (linux_proc_pid_is_stopped (pid
))
1046 if (debug_linux_nat
)
1047 fprintf_unfiltered (gdb_stdlog
,
1048 "LNPAW: Attaching to a stopped process\n");
1050 /* The process is definitely stopped. It is in a job control
1051 stop, unless the kernel predates the TASK_STOPPED /
1052 TASK_TRACED distinction, in which case it might be in a
1053 ptrace stop. Make sure it is in a ptrace stop; from there we
1054 can kill it, signal it, et cetera.
1056 First make sure there is a pending SIGSTOP. Since we are
1057 already attached, the process can not transition from stopped
1058 to running without a PTRACE_CONT; so we know this signal will
1059 go into the queue. The SIGSTOP generated by PTRACE_ATTACH is
1060 probably already in the queue (unless this kernel is old
1061 enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP
1062 is not an RT signal, it can only be queued once. */
1063 kill_lwp (pid
, SIGSTOP
);
1065 /* Finally, resume the stopped process. This will deliver the SIGSTOP
1066 (or a higher priority signal, just like normal PTRACE_ATTACH). */
1067 ptrace (PTRACE_CONT
, pid
, 0, 0);
1070 /* Make sure the initial process is stopped. The user-level threads
1071 layer might want to poke around in the inferior, and that won't
1072 work if things haven't stabilized yet. */
1073 new_pid
= my_waitpid (pid
, &status
, __WALL
);
1074 gdb_assert (pid
== new_pid
);
1076 if (!WIFSTOPPED (status
))
1078 /* The pid we tried to attach has apparently just exited. */
1079 if (debug_linux_nat
)
1080 fprintf_unfiltered (gdb_stdlog
, "LNPAW: Failed to stop %d: %s",
1081 pid
, status_to_str (status
));
1085 if (WSTOPSIG (status
) != SIGSTOP
)
1088 if (debug_linux_nat
)
1089 fprintf_unfiltered (gdb_stdlog
,
1090 "LNPAW: Received %s after attaching\n",
1091 status_to_str (status
));
1098 linux_nat_create_inferior (struct target_ops
*ops
,
1099 char *exec_file
, char *allargs
, char **env
,
1102 struct cleanup
*restore_personality
1103 = maybe_disable_address_space_randomization (disable_randomization
);
1105 /* The fork_child mechanism is synchronous and calls target_wait, so
1106 we have to mask the async mode. */
1108 /* Make sure we report all signals during startup. */
1109 linux_nat_pass_signals (ops
, 0, NULL
);
1111 linux_ops
->to_create_inferior (ops
, exec_file
, allargs
, env
, from_tty
);
1113 do_cleanups (restore_personality
);
1116 /* Callback for linux_proc_attach_tgid_threads. Attach to PTID if not
1117 already attached. Returns true if a new LWP is found, false
1121 attach_proc_task_lwp_callback (ptid_t ptid
)
1123 struct lwp_info
*lp
;
1125 /* Ignore LWPs we're already attached to. */
1126 lp
= find_lwp_pid (ptid
);
1129 int lwpid
= ptid_get_lwp (ptid
);
1131 if (ptrace (PTRACE_ATTACH
, lwpid
, 0, 0) < 0)
1135 /* Be quiet if we simply raced with the thread exiting.
1136 EPERM is returned if the thread's task still exists, and
1137 is marked as exited or zombie, as well as other
1138 conditions, so in that case, confirm the status in
1139 /proc/PID/status. */
1141 || (err
== EPERM
&& linux_proc_pid_is_gone (lwpid
)))
1143 if (debug_linux_nat
)
1145 fprintf_unfiltered (gdb_stdlog
,
1146 "Cannot attach to lwp %d: "
1147 "thread is gone (%d: %s)\n",
1148 lwpid
, err
, safe_strerror (err
));
1153 warning (_("Cannot attach to lwp %d: %s"),
1155 linux_ptrace_attach_fail_reason_string (ptid
,
1161 if (debug_linux_nat
)
1162 fprintf_unfiltered (gdb_stdlog
,
1163 "PTRACE_ATTACH %s, 0, 0 (OK)\n",
1164 target_pid_to_str (ptid
));
1166 lp
= add_lwp (ptid
);
1168 /* The next time we wait for this LWP we'll see a SIGSTOP as
1169 PTRACE_ATTACH brings it to a halt. */
1172 /* We need to wait for a stop before being able to make the
1173 next ptrace call on this LWP. */
1174 lp
->must_set_ptrace_flags
= 1;
1183 linux_nat_attach (struct target_ops
*ops
, const char *args
, int from_tty
)
1185 struct lwp_info
*lp
;
1189 /* Make sure we report all signals during attach. */
1190 linux_nat_pass_signals (ops
, 0, NULL
);
1194 linux_ops
->to_attach (ops
, args
, from_tty
);
1196 CATCH (ex
, RETURN_MASK_ERROR
)
1198 pid_t pid
= parse_pid_to_attach (args
);
1199 struct buffer buffer
;
1200 char *message
, *buffer_s
;
1202 message
= xstrdup (ex
.message
);
1203 make_cleanup (xfree
, message
);
1205 buffer_init (&buffer
);
1206 linux_ptrace_attach_fail_reason (pid
, &buffer
);
1208 buffer_grow_str0 (&buffer
, "");
1209 buffer_s
= buffer_finish (&buffer
);
1210 make_cleanup (xfree
, buffer_s
);
1212 if (*buffer_s
!= '\0')
1213 throw_error (ex
.error
, "warning: %s\n%s", buffer_s
, message
);
1215 throw_error (ex
.error
, "%s", message
);
1219 /* The ptrace base target adds the main thread with (pid,0,0)
1220 format. Decorate it with lwp info. */
1221 ptid
= ptid_build (ptid_get_pid (inferior_ptid
),
1222 ptid_get_pid (inferior_ptid
),
1224 thread_change_ptid (inferior_ptid
, ptid
);
1226 /* Add the initial process as the first LWP to the list. */
1227 lp
= add_initial_lwp (ptid
);
1229 status
= linux_nat_post_attach_wait (lp
->ptid
, 1, &lp
->signalled
);
1230 if (!WIFSTOPPED (status
))
1232 if (WIFEXITED (status
))
1234 int exit_code
= WEXITSTATUS (status
);
1236 target_terminal_ours ();
1237 target_mourn_inferior ();
1239 error (_("Unable to attach: program exited normally."));
1241 error (_("Unable to attach: program exited with code %d."),
1244 else if (WIFSIGNALED (status
))
1246 enum gdb_signal signo
;
1248 target_terminal_ours ();
1249 target_mourn_inferior ();
1251 signo
= gdb_signal_from_host (WTERMSIG (status
));
1252 error (_("Unable to attach: program terminated with signal "
1254 gdb_signal_to_name (signo
),
1255 gdb_signal_to_string (signo
));
1258 internal_error (__FILE__
, __LINE__
,
1259 _("unexpected status %d for PID %ld"),
1260 status
, (long) ptid_get_lwp (ptid
));
1265 /* Save the wait status to report later. */
1267 if (debug_linux_nat
)
1268 fprintf_unfiltered (gdb_stdlog
,
1269 "LNA: waitpid %ld, saving status %s\n",
1270 (long) ptid_get_pid (lp
->ptid
), status_to_str (status
));
1272 lp
->status
= status
;
1274 /* We must attach to every LWP. If /proc is mounted, use that to
1275 find them now. The inferior may be using raw clone instead of
1276 using pthreads. But even if it is using pthreads, thread_db
1277 walks structures in the inferior's address space to find the list
1278 of threads/LWPs, and those structures may well be corrupted.
1279 Note that once thread_db is loaded, we'll still use it to list
1280 threads and associate pthread info with each LWP. */
1281 linux_proc_attach_tgid_threads (ptid_get_pid (lp
->ptid
),
1282 attach_proc_task_lwp_callback
);
1284 if (target_can_async_p ())
1288 /* Get pending status of LP. */
1290 get_pending_status (struct lwp_info
*lp
, int *status
)
1292 enum gdb_signal signo
= GDB_SIGNAL_0
;
1294 /* If we paused threads momentarily, we may have stored pending
1295 events in lp->status or lp->waitstatus (see stop_wait_callback),
1296 and GDB core hasn't seen any signal for those threads.
1297 Otherwise, the last signal reported to the core is found in the
1298 thread object's stop_signal.
1300 There's a corner case that isn't handled here at present. Only
1301 if the thread stopped with a TARGET_WAITKIND_STOPPED does
1302 stop_signal make sense as a real signal to pass to the inferior.
1303 Some catchpoint related events, like
1304 TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set
1305 to GDB_SIGNAL_SIGTRAP when the catchpoint triggers. But,
1306 those traps are debug API (ptrace in our case) related and
1307 induced; the inferior wouldn't see them if it wasn't being
1308 traced. Hence, we should never pass them to the inferior, even
1309 when set to pass state. Since this corner case isn't handled by
1310 infrun.c when proceeding with a signal, for consistency, neither
1311 do we handle it here (or elsewhere in the file we check for
1312 signal pass state). Normally SIGTRAP isn't set to pass state, so
1313 this is really a corner case. */
1315 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
1316 signo
= GDB_SIGNAL_0
; /* a pending ptrace event, not a real signal. */
1317 else if (lp
->status
)
1318 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1319 else if (target_is_non_stop_p () && !is_executing (lp
->ptid
))
1321 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1323 if (tp
->suspend
.waitstatus_pending_p
)
1324 signo
= tp
->suspend
.waitstatus
.value
.sig
;
1326 signo
= tp
->suspend
.stop_signal
;
1328 else if (!target_is_non_stop_p ())
1330 struct target_waitstatus last
;
1333 get_last_target_status (&last_ptid
, &last
);
1335 if (ptid_get_lwp (lp
->ptid
) == ptid_get_lwp (last_ptid
))
1337 struct thread_info
*tp
= find_thread_ptid (lp
->ptid
);
1339 signo
= tp
->suspend
.stop_signal
;
1345 if (signo
== GDB_SIGNAL_0
)
1347 if (debug_linux_nat
)
1348 fprintf_unfiltered (gdb_stdlog
,
1349 "GPT: lwp %s has no pending signal\n",
1350 target_pid_to_str (lp
->ptid
));
1352 else if (!signal_pass_state (signo
))
1354 if (debug_linux_nat
)
1355 fprintf_unfiltered (gdb_stdlog
,
1356 "GPT: lwp %s had signal %s, "
1357 "but it is in no pass state\n",
1358 target_pid_to_str (lp
->ptid
),
1359 gdb_signal_to_string (signo
));
1363 *status
= W_STOPCODE (gdb_signal_to_host (signo
));
1365 if (debug_linux_nat
)
1366 fprintf_unfiltered (gdb_stdlog
,
1367 "GPT: lwp %s has pending signal %s\n",
1368 target_pid_to_str (lp
->ptid
),
1369 gdb_signal_to_string (signo
));
1376 detach_callback (struct lwp_info
*lp
, void *data
)
1378 gdb_assert (lp
->status
== 0 || WIFSTOPPED (lp
->status
));
1380 if (debug_linux_nat
&& lp
->status
)
1381 fprintf_unfiltered (gdb_stdlog
, "DC: Pending %s for %s on detach.\n",
1382 strsignal (WSTOPSIG (lp
->status
)),
1383 target_pid_to_str (lp
->ptid
));
1385 /* If there is a pending SIGSTOP, get rid of it. */
1388 if (debug_linux_nat
)
1389 fprintf_unfiltered (gdb_stdlog
,
1390 "DC: Sending SIGCONT to %s\n",
1391 target_pid_to_str (lp
->ptid
));
1393 kill_lwp (ptid_get_lwp (lp
->ptid
), SIGCONT
);
1397 /* We don't actually detach from the LWP that has an id equal to the
1398 overall process id just yet. */
1399 if (ptid_get_lwp (lp
->ptid
) != ptid_get_pid (lp
->ptid
))
1403 /* Pass on any pending signal for this LWP. */
1404 get_pending_status (lp
, &status
);
1406 if (linux_nat_prepare_to_resume
!= NULL
)
1407 linux_nat_prepare_to_resume (lp
);
1409 if (ptrace (PTRACE_DETACH
, ptid_get_lwp (lp
->ptid
), 0,
1410 WSTOPSIG (status
)) < 0)
1411 error (_("Can't detach %s: %s"), target_pid_to_str (lp
->ptid
),
1412 safe_strerror (errno
));
1414 if (debug_linux_nat
)
1415 fprintf_unfiltered (gdb_stdlog
,
1416 "PTRACE_DETACH (%s, %s, 0) (OK)\n",
1417 target_pid_to_str (lp
->ptid
),
1418 strsignal (WSTOPSIG (status
)));
1420 delete_lwp (lp
->ptid
);
1427 linux_nat_detach (struct target_ops
*ops
, const char *args
, int from_tty
)
1431 struct lwp_info
*main_lwp
;
1433 pid
= ptid_get_pid (inferior_ptid
);
1435 /* Don't unregister from the event loop, as there may be other
1436 inferiors running. */
1438 /* Stop all threads before detaching. ptrace requires that the
1439 thread is stopped to sucessfully detach. */
1440 iterate_over_lwps (pid_to_ptid (pid
), stop_callback
, NULL
);
1441 /* ... and wait until all of them have reported back that
1442 they're no longer running. */
1443 iterate_over_lwps (pid_to_ptid (pid
), stop_wait_callback
, NULL
);
1445 iterate_over_lwps (pid_to_ptid (pid
), detach_callback
, NULL
);
1447 /* Only the initial process should be left right now. */
1448 gdb_assert (num_lwps (ptid_get_pid (inferior_ptid
)) == 1);
1450 main_lwp
= find_lwp_pid (pid_to_ptid (pid
));
1452 /* Pass on any pending signal for the last LWP. */
1453 if ((args
== NULL
|| *args
== '\0')
1454 && get_pending_status (main_lwp
, &status
) != -1
1455 && WIFSTOPPED (status
))
1459 /* Put the signal number in ARGS so that inf_ptrace_detach will
1460 pass it along with PTRACE_DETACH. */
1461 tem
= (char *) alloca (8);
1462 xsnprintf (tem
, 8, "%d", (int) WSTOPSIG (status
));
1464 if (debug_linux_nat
)
1465 fprintf_unfiltered (gdb_stdlog
,
1466 "LND: Sending signal %s to %s\n",
1468 target_pid_to_str (main_lwp
->ptid
));
1471 if (linux_nat_prepare_to_resume
!= NULL
)
1472 linux_nat_prepare_to_resume (main_lwp
);
1473 delete_lwp (main_lwp
->ptid
);
1475 if (forks_exist_p ())
1477 /* Multi-fork case. The current inferior_ptid is being detached
1478 from, but there are other viable forks to debug. Detach from
1479 the current fork, and context-switch to the first
1481 linux_fork_detach (args
, from_tty
);
1484 linux_ops
->to_detach (ops
, args
, from_tty
);
1487 /* Resume execution of the inferior process. If STEP is nonzero,
1488 single-step it. If SIGNAL is nonzero, give it that signal. */
1491 linux_resume_one_lwp_throw (struct lwp_info
*lp
, int step
,
1492 enum gdb_signal signo
)
1496 /* stop_pc doubles as the PC the LWP had when it was last resumed.
1497 We only presently need that if the LWP is stepped though (to
1498 handle the case of stepping a breakpoint instruction). */
1501 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
1503 lp
->stop_pc
= regcache_read_pc (regcache
);
1508 if (linux_nat_prepare_to_resume
!= NULL
)
1509 linux_nat_prepare_to_resume (lp
);
1510 linux_ops
->to_resume (linux_ops
, lp
->ptid
, step
, signo
);
1512 /* Successfully resumed. Clear state that no longer makes sense,
1513 and mark the LWP as running. Must not do this before resuming
1514 otherwise if that fails other code will be confused. E.g., we'd
1515 later try to stop the LWP and hang forever waiting for a stop
1516 status. Note that we must not throw after this is cleared,
1517 otherwise handle_zombie_lwp_error would get confused. */
1520 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1521 registers_changed_ptid (lp
->ptid
);
1524 /* Called when we try to resume a stopped LWP and that errors out. If
1525 the LWP is no longer in ptrace-stopped state (meaning it's zombie,
1526 or about to become), discard the error, clear any pending status
1527 the LWP may have, and return true (we'll collect the exit status
1528 soon enough). Otherwise, return false. */
1531 check_ptrace_stopped_lwp_gone (struct lwp_info
*lp
)
1533 /* If we get an error after resuming the LWP successfully, we'd
1534 confuse !T state for the LWP being gone. */
1535 gdb_assert (lp
->stopped
);
1537 /* We can't just check whether the LWP is in 'Z (Zombie)' state,
1538 because even if ptrace failed with ESRCH, the tracee may be "not
1539 yet fully dead", but already refusing ptrace requests. In that
1540 case the tracee has 'R (Running)' state for a little bit
1541 (observed in Linux 3.18). See also the note on ESRCH in the
1542 ptrace(2) man page. Instead, check whether the LWP has any state
1543 other than ptrace-stopped. */
1545 /* Don't assume anything if /proc/PID/status can't be read. */
1546 if (linux_proc_pid_is_trace_stopped_nowarn (ptid_get_lwp (lp
->ptid
)) == 0)
1548 lp
->stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
1550 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
1556 /* Like linux_resume_one_lwp_throw, but no error is thrown if the LWP
1557 disappears while we try to resume it. */
1560 linux_resume_one_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1564 linux_resume_one_lwp_throw (lp
, step
, signo
);
1566 CATCH (ex
, RETURN_MASK_ERROR
)
1568 if (!check_ptrace_stopped_lwp_gone (lp
))
1569 throw_exception (ex
);
1577 resume_lwp (struct lwp_info
*lp
, int step
, enum gdb_signal signo
)
1581 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
1583 if (inf
->vfork_child
!= NULL
)
1585 if (debug_linux_nat
)
1586 fprintf_unfiltered (gdb_stdlog
,
1587 "RC: Not resuming %s (vfork parent)\n",
1588 target_pid_to_str (lp
->ptid
));
1590 else if (!lwp_status_pending_p (lp
))
1592 if (debug_linux_nat
)
1593 fprintf_unfiltered (gdb_stdlog
,
1594 "RC: Resuming sibling %s, %s, %s\n",
1595 target_pid_to_str (lp
->ptid
),
1596 (signo
!= GDB_SIGNAL_0
1597 ? strsignal (gdb_signal_to_host (signo
))
1599 step
? "step" : "resume");
1601 linux_resume_one_lwp (lp
, step
, signo
);
1605 if (debug_linux_nat
)
1606 fprintf_unfiltered (gdb_stdlog
,
1607 "RC: Not resuming sibling %s (has pending)\n",
1608 target_pid_to_str (lp
->ptid
));
1613 if (debug_linux_nat
)
1614 fprintf_unfiltered (gdb_stdlog
,
1615 "RC: Not resuming sibling %s (not stopped)\n",
1616 target_pid_to_str (lp
->ptid
));
1620 /* Callback for iterate_over_lwps. If LWP is EXCEPT, do nothing.
1621 Resume LWP with the last stop signal, if it is in pass state. */
1624 linux_nat_resume_callback (struct lwp_info
*lp
, void *except
)
1626 enum gdb_signal signo
= GDB_SIGNAL_0
;
1633 struct thread_info
*thread
;
1635 thread
= find_thread_ptid (lp
->ptid
);
1638 signo
= thread
->suspend
.stop_signal
;
1639 thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
1643 resume_lwp (lp
, 0, signo
);
1648 resume_clear_callback (struct lwp_info
*lp
, void *data
)
1651 lp
->last_resume_kind
= resume_stop
;
1656 resume_set_callback (struct lwp_info
*lp
, void *data
)
1659 lp
->last_resume_kind
= resume_continue
;
1664 linux_nat_resume (struct target_ops
*ops
,
1665 ptid_t ptid
, int step
, enum gdb_signal signo
)
1667 struct lwp_info
*lp
;
1670 if (debug_linux_nat
)
1671 fprintf_unfiltered (gdb_stdlog
,
1672 "LLR: Preparing to %s %s, %s, inferior_ptid %s\n",
1673 step
? "step" : "resume",
1674 target_pid_to_str (ptid
),
1675 (signo
!= GDB_SIGNAL_0
1676 ? strsignal (gdb_signal_to_host (signo
)) : "0"),
1677 target_pid_to_str (inferior_ptid
));
1679 /* A specific PTID means `step only this process id'. */
1680 resume_many
= (ptid_equal (minus_one_ptid
, ptid
)
1681 || ptid_is_pid (ptid
));
1683 /* Mark the lwps we're resuming as resumed. */
1684 iterate_over_lwps (ptid
, resume_set_callback
, NULL
);
1686 /* See if it's the current inferior that should be handled
1689 lp
= find_lwp_pid (inferior_ptid
);
1691 lp
= find_lwp_pid (ptid
);
1692 gdb_assert (lp
!= NULL
);
1694 /* Remember if we're stepping. */
1695 lp
->last_resume_kind
= step
? resume_step
: resume_continue
;
1697 /* If we have a pending wait status for this thread, there is no
1698 point in resuming the process. But first make sure that
1699 linux_nat_wait won't preemptively handle the event - we
1700 should never take this short-circuit if we are going to
1701 leave LP running, since we have skipped resuming all the
1702 other threads. This bit of code needs to be synchronized
1703 with linux_nat_wait. */
1705 if (lp
->status
&& WIFSTOPPED (lp
->status
))
1708 && WSTOPSIG (lp
->status
)
1709 && sigismember (&pass_mask
, WSTOPSIG (lp
->status
)))
1711 if (debug_linux_nat
)
1712 fprintf_unfiltered (gdb_stdlog
,
1713 "LLR: Not short circuiting for ignored "
1714 "status 0x%x\n", lp
->status
);
1716 /* FIXME: What should we do if we are supposed to continue
1717 this thread with a signal? */
1718 gdb_assert (signo
== GDB_SIGNAL_0
);
1719 signo
= gdb_signal_from_host (WSTOPSIG (lp
->status
));
1724 if (lwp_status_pending_p (lp
))
1726 /* FIXME: What should we do if we are supposed to continue
1727 this thread with a signal? */
1728 gdb_assert (signo
== GDB_SIGNAL_0
);
1730 if (debug_linux_nat
)
1731 fprintf_unfiltered (gdb_stdlog
,
1732 "LLR: Short circuiting for status 0x%x\n",
1735 if (target_can_async_p ())
1738 /* Tell the event loop we have something to process. */
1745 iterate_over_lwps (ptid
, linux_nat_resume_callback
, lp
);
1747 if (debug_linux_nat
)
1748 fprintf_unfiltered (gdb_stdlog
,
1749 "LLR: %s %s, %s (resume event thread)\n",
1750 step
? "PTRACE_SINGLESTEP" : "PTRACE_CONT",
1751 target_pid_to_str (lp
->ptid
),
1752 (signo
!= GDB_SIGNAL_0
1753 ? strsignal (gdb_signal_to_host (signo
)) : "0"));
1755 linux_resume_one_lwp (lp
, step
, signo
);
1757 if (target_can_async_p ())
1761 /* Send a signal to an LWP. */
1764 kill_lwp (int lwpid
, int signo
)
1769 ret
= syscall (__NR_tkill
, lwpid
, signo
);
1770 if (errno
== ENOSYS
)
1772 /* If tkill fails, then we are not using nptl threads, a
1773 configuration we no longer support. */
1774 perror_with_name (("tkill"));
1779 /* Handle a GNU/Linux syscall trap wait response. If we see a syscall
1780 event, check if the core is interested in it: if not, ignore the
1781 event, and keep waiting; otherwise, we need to toggle the LWP's
1782 syscall entry/exit status, since the ptrace event itself doesn't
1783 indicate it, and report the trap to higher layers. */
1786 linux_handle_syscall_trap (struct lwp_info
*lp
, int stopping
)
1788 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1789 struct gdbarch
*gdbarch
= target_thread_architecture (lp
->ptid
);
1790 int syscall_number
= (int) gdbarch_get_syscall_number (gdbarch
, lp
->ptid
);
1794 /* If we're stopping threads, there's a SIGSTOP pending, which
1795 makes it so that the LWP reports an immediate syscall return,
1796 followed by the SIGSTOP. Skip seeing that "return" using
1797 PTRACE_CONT directly, and let stop_wait_callback collect the
1798 SIGSTOP. Later when the thread is resumed, a new syscall
1799 entry event. If we didn't do this (and returned 0), we'd
1800 leave a syscall entry pending, and our caller, by using
1801 PTRACE_CONT to collect the SIGSTOP, skips the syscall return
1802 itself. Later, when the user re-resumes this LWP, we'd see
1803 another syscall entry event and we'd mistake it for a return.
1805 If stop_wait_callback didn't force the SIGSTOP out of the LWP
1806 (leaving immediately with LWP->signalled set, without issuing
1807 a PTRACE_CONT), it would still be problematic to leave this
1808 syscall enter pending, as later when the thread is resumed,
1809 it would then see the same syscall exit mentioned above,
1810 followed by the delayed SIGSTOP, while the syscall didn't
1811 actually get to execute. It seems it would be even more
1812 confusing to the user. */
1814 if (debug_linux_nat
)
1815 fprintf_unfiltered (gdb_stdlog
,
1816 "LHST: ignoring syscall %d "
1817 "for LWP %ld (stopping threads), "
1818 "resuming with PTRACE_CONT for SIGSTOP\n",
1820 ptid_get_lwp (lp
->ptid
));
1822 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1823 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
1828 /* Always update the entry/return state, even if this particular
1829 syscall isn't interesting to the core now. In async mode,
1830 the user could install a new catchpoint for this syscall
1831 between syscall enter/return, and we'll need to know to
1832 report a syscall return if that happens. */
1833 lp
->syscall_state
= (lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1834 ? TARGET_WAITKIND_SYSCALL_RETURN
1835 : TARGET_WAITKIND_SYSCALL_ENTRY
);
1837 if (catch_syscall_enabled ())
1839 if (catching_syscall_number (syscall_number
))
1841 /* Alright, an event to report. */
1842 ourstatus
->kind
= lp
->syscall_state
;
1843 ourstatus
->value
.syscall_number
= syscall_number
;
1845 if (debug_linux_nat
)
1846 fprintf_unfiltered (gdb_stdlog
,
1847 "LHST: stopping for %s of syscall %d"
1850 == TARGET_WAITKIND_SYSCALL_ENTRY
1851 ? "entry" : "return",
1853 ptid_get_lwp (lp
->ptid
));
1857 if (debug_linux_nat
)
1858 fprintf_unfiltered (gdb_stdlog
,
1859 "LHST: ignoring %s of syscall %d "
1861 lp
->syscall_state
== TARGET_WAITKIND_SYSCALL_ENTRY
1862 ? "entry" : "return",
1864 ptid_get_lwp (lp
->ptid
));
1868 /* If we had been syscall tracing, and hence used PT_SYSCALL
1869 before on this LWP, it could happen that the user removes all
1870 syscall catchpoints before we get to process this event.
1871 There are two noteworthy issues here:
1873 - When stopped at a syscall entry event, resuming with
1874 PT_STEP still resumes executing the syscall and reports a
1877 - Only PT_SYSCALL catches syscall enters. If we last
1878 single-stepped this thread, then this event can't be a
1879 syscall enter. If we last single-stepped this thread, this
1880 has to be a syscall exit.
1882 The points above mean that the next resume, be it PT_STEP or
1883 PT_CONTINUE, can not trigger a syscall trace event. */
1884 if (debug_linux_nat
)
1885 fprintf_unfiltered (gdb_stdlog
,
1886 "LHST: caught syscall event "
1887 "with no syscall catchpoints."
1888 " %d for LWP %ld, ignoring\n",
1890 ptid_get_lwp (lp
->ptid
));
1891 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
1894 /* The core isn't interested in this event. For efficiency, avoid
1895 stopping all threads only to have the core resume them all again.
1896 Since we're not stopping threads, if we're still syscall tracing
1897 and not stepping, we can't use PTRACE_CONT here, as we'd miss any
1898 subsequent syscall. Simply resume using the inf-ptrace layer,
1899 which knows when to use PT_SYSCALL or PT_CONTINUE. */
1901 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
1905 /* Handle a GNU/Linux extended wait response. If we see a clone
1906 event, we need to add the new LWP to our list (and not report the
1907 trap to higher layers). This function returns non-zero if the
1908 event should be ignored and we should wait again. If STOPPING is
1909 true, the new LWP remains stopped, otherwise it is continued. */
1912 linux_handle_extended_wait (struct lwp_info
*lp
, int status
)
1914 int pid
= ptid_get_lwp (lp
->ptid
);
1915 struct target_waitstatus
*ourstatus
= &lp
->waitstatus
;
1916 int event
= linux_ptrace_get_extended_event (status
);
1918 /* All extended events we currently use are mid-syscall. Only
1919 PTRACE_EVENT_STOP is delivered more like a signal-stop, but
1920 you have to be using PTRACE_SEIZE to get that. */
1921 lp
->syscall_state
= TARGET_WAITKIND_SYSCALL_ENTRY
;
1923 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
1924 || event
== PTRACE_EVENT_CLONE
)
1926 unsigned long new_pid
;
1929 ptrace (PTRACE_GETEVENTMSG
, pid
, 0, &new_pid
);
1931 /* If we haven't already seen the new PID stop, wait for it now. */
1932 if (! pull_pid_from_list (&stopped_pids
, new_pid
, &status
))
1934 /* The new child has a pending SIGSTOP. We can't affect it until it
1935 hits the SIGSTOP, but we're already attached. */
1936 ret
= my_waitpid (new_pid
, &status
, __WALL
);
1938 perror_with_name (_("waiting for new child"));
1939 else if (ret
!= new_pid
)
1940 internal_error (__FILE__
, __LINE__
,
1941 _("wait returned unexpected PID %d"), ret
);
1942 else if (!WIFSTOPPED (status
))
1943 internal_error (__FILE__
, __LINE__
,
1944 _("wait returned unexpected status 0x%x"), status
);
1947 ourstatus
->value
.related_pid
= ptid_build (new_pid
, new_pid
, 0);
1949 if (event
== PTRACE_EVENT_FORK
|| event
== PTRACE_EVENT_VFORK
)
1951 /* The arch-specific native code may need to know about new
1952 forks even if those end up never mapped to an
1954 if (linux_nat_new_fork
!= NULL
)
1955 linux_nat_new_fork (lp
, new_pid
);
1958 if (event
== PTRACE_EVENT_FORK
1959 && linux_fork_checkpointing_p (ptid_get_pid (lp
->ptid
)))
1961 /* Handle checkpointing by linux-fork.c here as a special
1962 case. We don't want the follow-fork-mode or 'catch fork'
1963 to interfere with this. */
1965 /* This won't actually modify the breakpoint list, but will
1966 physically remove the breakpoints from the child. */
1967 detach_breakpoints (ptid_build (new_pid
, new_pid
, 0));
1969 /* Retain child fork in ptrace (stopped) state. */
1970 if (!find_fork_pid (new_pid
))
1973 /* Report as spurious, so that infrun doesn't want to follow
1974 this fork. We're actually doing an infcall in
1976 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
1978 /* Report the stop to the core. */
1982 if (event
== PTRACE_EVENT_FORK
)
1983 ourstatus
->kind
= TARGET_WAITKIND_FORKED
;
1984 else if (event
== PTRACE_EVENT_VFORK
)
1985 ourstatus
->kind
= TARGET_WAITKIND_VFORKED
;
1986 else if (event
== PTRACE_EVENT_CLONE
)
1988 struct lwp_info
*new_lp
;
1990 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
1992 if (debug_linux_nat
)
1993 fprintf_unfiltered (gdb_stdlog
,
1994 "LHEW: Got clone event "
1995 "from LWP %d, new child is LWP %ld\n",
1998 new_lp
= add_lwp (ptid_build (ptid_get_pid (lp
->ptid
), new_pid
, 0));
1999 new_lp
->stopped
= 1;
2000 new_lp
->resumed
= 1;
2002 /* If the thread_db layer is active, let it record the user
2003 level thread id and status, and add the thread to GDB's
2005 if (!thread_db_notice_clone (lp
->ptid
, new_lp
->ptid
))
2007 /* The process is not using thread_db. Add the LWP to
2009 target_post_attach (ptid_get_lwp (new_lp
->ptid
));
2010 add_thread (new_lp
->ptid
);
2013 /* Even if we're stopping the thread for some reason
2014 internal to this module, from the perspective of infrun
2015 and the user/frontend, this new thread is running until
2016 it next reports a stop. */
2017 set_running (new_lp
->ptid
, 1);
2018 set_executing (new_lp
->ptid
, 1);
2020 if (WSTOPSIG (status
) != SIGSTOP
)
2022 /* This can happen if someone starts sending signals to
2023 the new thread before it gets a chance to run, which
2024 have a lower number than SIGSTOP (e.g. SIGUSR1).
2025 This is an unlikely case, and harder to handle for
2026 fork / vfork than for clone, so we do not try - but
2027 we handle it for clone events here. */
2029 new_lp
->signalled
= 1;
2031 /* We created NEW_LP so it cannot yet contain STATUS. */
2032 gdb_assert (new_lp
->status
== 0);
2034 /* Save the wait status to report later. */
2035 if (debug_linux_nat
)
2036 fprintf_unfiltered (gdb_stdlog
,
2037 "LHEW: waitpid of new LWP %ld, "
2038 "saving status %s\n",
2039 (long) ptid_get_lwp (new_lp
->ptid
),
2040 status_to_str (status
));
2041 new_lp
->status
= status
;
2043 else if (report_thread_events
)
2045 new_lp
->waitstatus
.kind
= TARGET_WAITKIND_THREAD_CREATED
;
2046 new_lp
->status
= status
;
2055 if (event
== PTRACE_EVENT_EXEC
)
2057 if (debug_linux_nat
)
2058 fprintf_unfiltered (gdb_stdlog
,
2059 "LHEW: Got exec event from LWP %ld\n",
2060 ptid_get_lwp (lp
->ptid
));
2062 ourstatus
->kind
= TARGET_WAITKIND_EXECD
;
2063 ourstatus
->value
.execd_pathname
2064 = xstrdup (linux_child_pid_to_exec_file (NULL
, pid
));
2066 /* The thread that execed must have been resumed, but, when a
2067 thread execs, it changes its tid to the tgid, and the old
2068 tgid thread might have not been resumed. */
2073 if (event
== PTRACE_EVENT_VFORK_DONE
)
2075 if (current_inferior ()->waiting_for_vfork_done
)
2077 if (debug_linux_nat
)
2078 fprintf_unfiltered (gdb_stdlog
,
2079 "LHEW: Got expected PTRACE_EVENT_"
2080 "VFORK_DONE from LWP %ld: stopping\n",
2081 ptid_get_lwp (lp
->ptid
));
2083 ourstatus
->kind
= TARGET_WAITKIND_VFORK_DONE
;
2087 if (debug_linux_nat
)
2088 fprintf_unfiltered (gdb_stdlog
,
2089 "LHEW: Got PTRACE_EVENT_VFORK_DONE "
2090 "from LWP %ld: ignoring\n",
2091 ptid_get_lwp (lp
->ptid
));
2095 internal_error (__FILE__
, __LINE__
,
2096 _("unknown ptrace event %d"), event
);
2099 /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has
2103 wait_lwp (struct lwp_info
*lp
)
2107 int thread_dead
= 0;
2110 gdb_assert (!lp
->stopped
);
2111 gdb_assert (lp
->status
== 0);
2113 /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */
2114 block_child_signals (&prev_mask
);
2118 pid
= my_waitpid (ptid_get_lwp (lp
->ptid
), &status
, __WALL
| WNOHANG
);
2119 if (pid
== -1 && errno
== ECHILD
)
2121 /* The thread has previously exited. We need to delete it
2122 now because if this was a non-leader thread execing, we
2123 won't get an exit event. See comments on exec events at
2124 the top of the file. */
2126 if (debug_linux_nat
)
2127 fprintf_unfiltered (gdb_stdlog
, "WL: %s vanished.\n",
2128 target_pid_to_str (lp
->ptid
));
2133 /* Bugs 10970, 12702.
2134 Thread group leader may have exited in which case we'll lock up in
2135 waitpid if there are other threads, even if they are all zombies too.
2136 Basically, we're not supposed to use waitpid this way.
2137 tkill(pid,0) cannot be used here as it gets ESRCH for both
2138 for zombie and running processes.
2140 As a workaround, check if we're waiting for the thread group leader and
2141 if it's a zombie, and avoid calling waitpid if it is.
2143 This is racy, what if the tgl becomes a zombie right after we check?
2144 Therefore always use WNOHANG with sigsuspend - it is equivalent to
2145 waiting waitpid but linux_proc_pid_is_zombie is safe this way. */
2147 if (ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
)
2148 && linux_proc_pid_is_zombie (ptid_get_lwp (lp
->ptid
)))
2151 if (debug_linux_nat
)
2152 fprintf_unfiltered (gdb_stdlog
,
2153 "WL: Thread group leader %s vanished.\n",
2154 target_pid_to_str (lp
->ptid
));
2158 /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers
2159 get invoked despite our caller had them intentionally blocked by
2160 block_child_signals. This is sensitive only to the loop of
2161 linux_nat_wait_1 and there if we get called my_waitpid gets called
2162 again before it gets to sigsuspend so we can safely let the handlers
2163 get executed here. */
2165 if (debug_linux_nat
)
2166 fprintf_unfiltered (gdb_stdlog
, "WL: about to sigsuspend\n");
2167 sigsuspend (&suspend_mask
);
2170 restore_child_signals_mask (&prev_mask
);
2174 gdb_assert (pid
== ptid_get_lwp (lp
->ptid
));
2176 if (debug_linux_nat
)
2178 fprintf_unfiltered (gdb_stdlog
,
2179 "WL: waitpid %s received %s\n",
2180 target_pid_to_str (lp
->ptid
),
2181 status_to_str (status
));
2184 /* Check if the thread has exited. */
2185 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2187 if (report_thread_events
2188 || ptid_get_pid (lp
->ptid
) == ptid_get_lwp (lp
->ptid
))
2190 if (debug_linux_nat
)
2191 fprintf_unfiltered (gdb_stdlog
, "WL: LWP %d exited.\n",
2192 ptid_get_pid (lp
->ptid
));
2194 /* If this is the leader exiting, it means the whole
2195 process is gone. Store the status to report to the
2196 core. Store it in lp->waitstatus, because lp->status
2197 would be ambiguous (W_EXITCODE(0,0) == 0). */
2198 store_waitstatus (&lp
->waitstatus
, status
);
2203 if (debug_linux_nat
)
2204 fprintf_unfiltered (gdb_stdlog
, "WL: %s exited.\n",
2205 target_pid_to_str (lp
->ptid
));
2215 gdb_assert (WIFSTOPPED (status
));
2218 if (lp
->must_set_ptrace_flags
)
2220 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2221 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2223 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2224 lp
->must_set_ptrace_flags
= 0;
2227 /* Handle GNU/Linux's syscall SIGTRAPs. */
2228 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2230 /* No longer need the sysgood bit. The ptrace event ends up
2231 recorded in lp->waitstatus if we care for it. We can carry
2232 on handling the event like a regular SIGTRAP from here
2234 status
= W_STOPCODE (SIGTRAP
);
2235 if (linux_handle_syscall_trap (lp
, 1))
2236 return wait_lwp (lp
);
2240 /* Almost all other ptrace-stops are known to be outside of system
2241 calls, with further exceptions in linux_handle_extended_wait. */
2242 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2245 /* Handle GNU/Linux's extended waitstatus for trace events. */
2246 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2247 && linux_is_extended_waitstatus (status
))
2249 if (debug_linux_nat
)
2250 fprintf_unfiltered (gdb_stdlog
,
2251 "WL: Handling extended status 0x%06x\n",
2253 linux_handle_extended_wait (lp
, status
);
2260 /* Send a SIGSTOP to LP. */
2263 stop_callback (struct lwp_info
*lp
, void *data
)
2265 if (!lp
->stopped
&& !lp
->signalled
)
2269 if (debug_linux_nat
)
2271 fprintf_unfiltered (gdb_stdlog
,
2272 "SC: kill %s **<SIGSTOP>**\n",
2273 target_pid_to_str (lp
->ptid
));
2276 ret
= kill_lwp (ptid_get_lwp (lp
->ptid
), SIGSTOP
);
2277 if (debug_linux_nat
)
2279 fprintf_unfiltered (gdb_stdlog
,
2280 "SC: lwp kill %d %s\n",
2282 errno
? safe_strerror (errno
) : "ERRNO-OK");
2286 gdb_assert (lp
->status
== 0);
2292 /* Request a stop on LWP. */
2295 linux_stop_lwp (struct lwp_info
*lwp
)
2297 stop_callback (lwp
, NULL
);
2300 /* See linux-nat.h */
2303 linux_stop_and_wait_all_lwps (void)
2305 /* Stop all LWP's ... */
2306 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
2308 /* ... and wait until all of them have reported back that
2309 they're no longer running. */
2310 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
2313 /* See linux-nat.h */
2316 linux_unstop_all_lwps (void)
2318 iterate_over_lwps (minus_one_ptid
,
2319 resume_stopped_resumed_lwps
, &minus_one_ptid
);
2322 /* Return non-zero if LWP PID has a pending SIGINT. */
2325 linux_nat_has_pending_sigint (int pid
)
2327 sigset_t pending
, blocked
, ignored
;
2329 linux_proc_pending_signals (pid
, &pending
, &blocked
, &ignored
);
2331 if (sigismember (&pending
, SIGINT
)
2332 && !sigismember (&ignored
, SIGINT
))
2338 /* Set a flag in LP indicating that we should ignore its next SIGINT. */
2341 set_ignore_sigint (struct lwp_info
*lp
, void *data
)
2343 /* If a thread has a pending SIGINT, consume it; otherwise, set a
2344 flag to consume the next one. */
2345 if (lp
->stopped
&& lp
->status
!= 0 && WIFSTOPPED (lp
->status
)
2346 && WSTOPSIG (lp
->status
) == SIGINT
)
2349 lp
->ignore_sigint
= 1;
2354 /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag.
2355 This function is called after we know the LWP has stopped; if the LWP
2356 stopped before the expected SIGINT was delivered, then it will never have
2357 arrived. Also, if the signal was delivered to a shared queue and consumed
2358 by a different thread, it will never be delivered to this LWP. */
2361 maybe_clear_ignore_sigint (struct lwp_info
*lp
)
2363 if (!lp
->ignore_sigint
)
2366 if (!linux_nat_has_pending_sigint (ptid_get_lwp (lp
->ptid
)))
2368 if (debug_linux_nat
)
2369 fprintf_unfiltered (gdb_stdlog
,
2370 "MCIS: Clearing bogus flag for %s\n",
2371 target_pid_to_str (lp
->ptid
));
2372 lp
->ignore_sigint
= 0;
2376 /* Fetch the possible triggered data watchpoint info and store it in
2379 On some archs, like x86, that use debug registers to set
2380 watchpoints, it's possible that the way to know which watched
2381 address trapped, is to check the register that is used to select
2382 which address to watch. Problem is, between setting the watchpoint
2383 and reading back which data address trapped, the user may change
2384 the set of watchpoints, and, as a consequence, GDB changes the
2385 debug registers in the inferior. To avoid reading back a stale
2386 stopped-data-address when that happens, we cache in LP the fact
2387 that a watchpoint trapped, and the corresponding data address, as
2388 soon as we see LP stop with a SIGTRAP. If GDB changes the debug
2389 registers meanwhile, we have the cached data we can rely on. */
2392 check_stopped_by_watchpoint (struct lwp_info
*lp
)
2394 struct cleanup
*old_chain
;
2396 if (linux_ops
->to_stopped_by_watchpoint
== NULL
)
2399 old_chain
= save_inferior_ptid ();
2400 inferior_ptid
= lp
->ptid
;
2402 if (linux_ops
->to_stopped_by_watchpoint (linux_ops
))
2404 lp
->stop_reason
= TARGET_STOPPED_BY_WATCHPOINT
;
2406 if (linux_ops
->to_stopped_data_address
!= NULL
)
2407 lp
->stopped_data_address_p
=
2408 linux_ops
->to_stopped_data_address (¤t_target
,
2409 &lp
->stopped_data_address
);
2411 lp
->stopped_data_address_p
= 0;
2414 do_cleanups (old_chain
);
2416 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2419 /* Returns true if the LWP had stopped for a watchpoint. */
2422 linux_nat_stopped_by_watchpoint (struct target_ops
*ops
)
2424 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2426 gdb_assert (lp
!= NULL
);
2428 return lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
;
2432 linux_nat_stopped_data_address (struct target_ops
*ops
, CORE_ADDR
*addr_p
)
2434 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2436 gdb_assert (lp
!= NULL
);
2438 *addr_p
= lp
->stopped_data_address
;
2440 return lp
->stopped_data_address_p
;
2443 /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */
2446 sigtrap_is_event (int status
)
2448 return WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
;
2451 /* Set alternative SIGTRAP-like events recognizer. If
2452 breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be
2456 linux_nat_set_status_is_event (struct target_ops
*t
,
2457 int (*status_is_event
) (int status
))
2459 linux_nat_status_is_event
= status_is_event
;
2462 /* Wait until LP is stopped. */
2465 stop_wait_callback (struct lwp_info
*lp
, void *data
)
2467 struct inferior
*inf
= find_inferior_ptid (lp
->ptid
);
2469 /* If this is a vfork parent, bail out, it is not going to report
2470 any SIGSTOP until the vfork is done with. */
2471 if (inf
->vfork_child
!= NULL
)
2478 status
= wait_lwp (lp
);
2482 if (lp
->ignore_sigint
&& WIFSTOPPED (status
)
2483 && WSTOPSIG (status
) == SIGINT
)
2485 lp
->ignore_sigint
= 0;
2488 ptrace (PTRACE_CONT
, ptid_get_lwp (lp
->ptid
), 0, 0);
2490 if (debug_linux_nat
)
2491 fprintf_unfiltered (gdb_stdlog
,
2492 "PTRACE_CONT %s, 0, 0 (%s) "
2493 "(discarding SIGINT)\n",
2494 target_pid_to_str (lp
->ptid
),
2495 errno
? safe_strerror (errno
) : "OK");
2497 return stop_wait_callback (lp
, NULL
);
2500 maybe_clear_ignore_sigint (lp
);
2502 if (WSTOPSIG (status
) != SIGSTOP
)
2504 /* The thread was stopped with a signal other than SIGSTOP. */
2506 if (debug_linux_nat
)
2507 fprintf_unfiltered (gdb_stdlog
,
2508 "SWC: Pending event %s in %s\n",
2509 status_to_str ((int) status
),
2510 target_pid_to_str (lp
->ptid
));
2512 /* Save the sigtrap event. */
2513 lp
->status
= status
;
2514 gdb_assert (lp
->signalled
);
2515 save_stop_reason (lp
);
2519 /* We caught the SIGSTOP that we intended to catch, so
2520 there's no SIGSTOP pending. */
2522 if (debug_linux_nat
)
2523 fprintf_unfiltered (gdb_stdlog
,
2524 "SWC: Expected SIGSTOP caught for %s.\n",
2525 target_pid_to_str (lp
->ptid
));
2527 /* Reset SIGNALLED only after the stop_wait_callback call
2528 above as it does gdb_assert on SIGNALLED. */
2536 /* Return non-zero if LP has a wait status pending. Discard the
2537 pending event and resume the LWP if the event that originally
2538 caused the stop became uninteresting. */
2541 status_callback (struct lwp_info
*lp
, void *data
)
2543 /* Only report a pending wait status if we pretend that this has
2544 indeed been resumed. */
2548 if (!lwp_status_pending_p (lp
))
2551 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
2552 || lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2554 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
2558 pc
= regcache_read_pc (regcache
);
2560 if (pc
!= lp
->stop_pc
)
2562 if (debug_linux_nat
)
2563 fprintf_unfiltered (gdb_stdlog
,
2564 "SC: PC of %s changed. was=%s, now=%s\n",
2565 target_pid_to_str (lp
->ptid
),
2566 paddress (target_gdbarch (), lp
->stop_pc
),
2567 paddress (target_gdbarch (), pc
));
2571 #if !USE_SIGTRAP_SIGINFO
2572 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2574 if (debug_linux_nat
)
2575 fprintf_unfiltered (gdb_stdlog
,
2576 "SC: previous breakpoint of %s, at %s gone\n",
2577 target_pid_to_str (lp
->ptid
),
2578 paddress (target_gdbarch (), lp
->stop_pc
));
2586 if (debug_linux_nat
)
2587 fprintf_unfiltered (gdb_stdlog
,
2588 "SC: pending event of %s cancelled.\n",
2589 target_pid_to_str (lp
->ptid
));
2592 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
2600 /* Count the LWP's that have had events. */
2603 count_events_callback (struct lwp_info
*lp
, void *data
)
2605 int *count
= (int *) data
;
2607 gdb_assert (count
!= NULL
);
2609 /* Select only resumed LWPs that have an event pending. */
2610 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2616 /* Select the LWP (if any) that is currently being single-stepped. */
2619 select_singlestep_lwp_callback (struct lwp_info
*lp
, void *data
)
2621 if (lp
->last_resume_kind
== resume_step
2628 /* Returns true if LP has a status pending. */
2631 lwp_status_pending_p (struct lwp_info
*lp
)
2633 /* We check for lp->waitstatus in addition to lp->status, because we
2634 can have pending process exits recorded in lp->status and
2635 W_EXITCODE(0,0) happens to be 0. */
2636 return lp
->status
!= 0 || lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
;
2639 /* Select the Nth LWP that has had an event. */
2642 select_event_lwp_callback (struct lwp_info
*lp
, void *data
)
2644 int *selector
= (int *) data
;
2646 gdb_assert (selector
!= NULL
);
2648 /* Select only resumed LWPs that have an event pending. */
2649 if (lp
->resumed
&& lwp_status_pending_p (lp
))
2650 if ((*selector
)-- == 0)
2656 /* Called when the LWP stopped for a signal/trap. If it stopped for a
2657 trap check what caused it (breakpoint, watchpoint, trace, etc.),
2658 and save the result in the LWP's stop_reason field. If it stopped
2659 for a breakpoint, decrement the PC if necessary on the lwp's
2663 save_stop_reason (struct lwp_info
*lp
)
2665 struct regcache
*regcache
;
2666 struct gdbarch
*gdbarch
;
2669 #if USE_SIGTRAP_SIGINFO
2673 gdb_assert (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
);
2674 gdb_assert (lp
->status
!= 0);
2676 if (!linux_nat_status_is_event (lp
->status
))
2679 regcache
= get_thread_regcache (lp
->ptid
);
2680 gdbarch
= get_regcache_arch (regcache
);
2682 pc
= regcache_read_pc (regcache
);
2683 sw_bp_pc
= pc
- gdbarch_decr_pc_after_break (gdbarch
);
2685 #if USE_SIGTRAP_SIGINFO
2686 if (linux_nat_get_siginfo (lp
->ptid
, &siginfo
))
2688 if (siginfo
.si_signo
== SIGTRAP
)
2690 if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
)
2691 && GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2693 /* The si_code is ambiguous on this arch -- check debug
2695 if (!check_stopped_by_watchpoint (lp
))
2696 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2698 else if (GDB_ARCH_IS_TRAP_BRKPT (siginfo
.si_code
))
2700 /* If we determine the LWP stopped for a SW breakpoint,
2701 trust it. Particularly don't check watchpoint
2702 registers, because at least on s390, we'd find
2703 stopped-by-watchpoint as long as there's a watchpoint
2705 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2707 else if (GDB_ARCH_IS_TRAP_HWBKPT (siginfo
.si_code
))
2709 /* This can indicate either a hardware breakpoint or
2710 hardware watchpoint. Check debug registers. */
2711 if (!check_stopped_by_watchpoint (lp
))
2712 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2714 else if (siginfo
.si_code
== TRAP_TRACE
)
2716 if (debug_linux_nat
)
2717 fprintf_unfiltered (gdb_stdlog
,
2718 "CSBB: %s stopped by trace\n",
2719 target_pid_to_str (lp
->ptid
));
2721 /* We may have single stepped an instruction that
2722 triggered a watchpoint. In that case, on some
2723 architectures (such as x86), instead of TRAP_HWBKPT,
2724 si_code indicates TRAP_TRACE, and we need to check
2725 the debug registers separately. */
2726 check_stopped_by_watchpoint (lp
);
2731 if ((!lp
->step
|| lp
->stop_pc
== sw_bp_pc
)
2732 && software_breakpoint_inserted_here_p (get_regcache_aspace (regcache
),
2735 /* The LWP was either continued, or stepped a software
2736 breakpoint instruction. */
2737 lp
->stop_reason
= TARGET_STOPPED_BY_SW_BREAKPOINT
;
2740 if (hardware_breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
2741 lp
->stop_reason
= TARGET_STOPPED_BY_HW_BREAKPOINT
;
2743 if (lp
->stop_reason
== TARGET_STOPPED_BY_NO_REASON
)
2744 check_stopped_by_watchpoint (lp
);
2747 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
)
2749 if (debug_linux_nat
)
2750 fprintf_unfiltered (gdb_stdlog
,
2751 "CSBB: %s stopped by software breakpoint\n",
2752 target_pid_to_str (lp
->ptid
));
2754 /* Back up the PC if necessary. */
2756 regcache_write_pc (regcache
, sw_bp_pc
);
2758 /* Update this so we record the correct stop PC below. */
2761 else if (lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
)
2763 if (debug_linux_nat
)
2764 fprintf_unfiltered (gdb_stdlog
,
2765 "CSBB: %s stopped by hardware breakpoint\n",
2766 target_pid_to_str (lp
->ptid
));
2768 else if (lp
->stop_reason
== TARGET_STOPPED_BY_WATCHPOINT
)
2770 if (debug_linux_nat
)
2771 fprintf_unfiltered (gdb_stdlog
,
2772 "CSBB: %s stopped by hardware watchpoint\n",
2773 target_pid_to_str (lp
->ptid
));
2780 /* Returns true if the LWP had stopped for a software breakpoint. */
2783 linux_nat_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2785 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2787 gdb_assert (lp
!= NULL
);
2789 return lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
;
2792 /* Implement the supports_stopped_by_sw_breakpoint method. */
2795 linux_nat_supports_stopped_by_sw_breakpoint (struct target_ops
*ops
)
2797 return USE_SIGTRAP_SIGINFO
;
2800 /* Returns true if the LWP had stopped for a hardware
2801 breakpoint/watchpoint. */
2804 linux_nat_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2806 struct lwp_info
*lp
= find_lwp_pid (inferior_ptid
);
2808 gdb_assert (lp
!= NULL
);
2810 return lp
->stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
;
2813 /* Implement the supports_stopped_by_hw_breakpoint method. */
2816 linux_nat_supports_stopped_by_hw_breakpoint (struct target_ops
*ops
)
2818 return USE_SIGTRAP_SIGINFO
;
2821 /* Select one LWP out of those that have events pending. */
2824 select_event_lwp (ptid_t filter
, struct lwp_info
**orig_lp
, int *status
)
2827 int random_selector
;
2828 struct lwp_info
*event_lp
= NULL
;
2830 /* Record the wait status for the original LWP. */
2831 (*orig_lp
)->status
= *status
;
2833 /* In all-stop, give preference to the LWP that is being
2834 single-stepped. There will be at most one, and it will be the
2835 LWP that the core is most interested in. If we didn't do this,
2836 then we'd have to handle pending step SIGTRAPs somehow in case
2837 the core later continues the previously-stepped thread, as
2838 otherwise we'd report the pending SIGTRAP then, and the core, not
2839 having stepped the thread, wouldn't understand what the trap was
2840 for, and therefore would report it to the user as a random
2842 if (!target_is_non_stop_p ())
2844 event_lp
= iterate_over_lwps (filter
,
2845 select_singlestep_lwp_callback
, NULL
);
2846 if (event_lp
!= NULL
)
2848 if (debug_linux_nat
)
2849 fprintf_unfiltered (gdb_stdlog
,
2850 "SEL: Select single-step %s\n",
2851 target_pid_to_str (event_lp
->ptid
));
2855 if (event_lp
== NULL
)
2857 /* Pick one at random, out of those which have had events. */
2859 /* First see how many events we have. */
2860 iterate_over_lwps (filter
, count_events_callback
, &num_events
);
2861 gdb_assert (num_events
> 0);
2863 /* Now randomly pick a LWP out of those that have had
2865 random_selector
= (int)
2866 ((num_events
* (double) rand ()) / (RAND_MAX
+ 1.0));
2868 if (debug_linux_nat
&& num_events
> 1)
2869 fprintf_unfiltered (gdb_stdlog
,
2870 "SEL: Found %d events, selecting #%d\n",
2871 num_events
, random_selector
);
2873 event_lp
= iterate_over_lwps (filter
,
2874 select_event_lwp_callback
,
2878 if (event_lp
!= NULL
)
2880 /* Switch the event LWP. */
2881 *orig_lp
= event_lp
;
2882 *status
= event_lp
->status
;
2885 /* Flush the wait status for the event LWP. */
2886 (*orig_lp
)->status
= 0;
2889 /* Return non-zero if LP has been resumed. */
2892 resumed_callback (struct lwp_info
*lp
, void *data
)
2897 /* Check if we should go on and pass this event to common code.
2898 Return the affected lwp if we are, or NULL otherwise. */
2900 static struct lwp_info
*
2901 linux_nat_filter_event (int lwpid
, int status
)
2903 struct lwp_info
*lp
;
2904 int event
= linux_ptrace_get_extended_event (status
);
2906 lp
= find_lwp_pid (pid_to_ptid (lwpid
));
2908 /* Check for stop events reported by a process we didn't already
2909 know about - anything not already in our LWP list.
2911 If we're expecting to receive stopped processes after
2912 fork, vfork, and clone events, then we'll just add the
2913 new one to our list and go back to waiting for the event
2914 to be reported - the stopped process might be returned
2915 from waitpid before or after the event is.
2917 But note the case of a non-leader thread exec'ing after the
2918 leader having exited, and gone from our lists. The non-leader
2919 thread changes its tid to the tgid. */
2921 if (WIFSTOPPED (status
) && lp
== NULL
2922 && (WSTOPSIG (status
) == SIGTRAP
&& event
== PTRACE_EVENT_EXEC
))
2924 /* A multi-thread exec after we had seen the leader exiting. */
2925 if (debug_linux_nat
)
2926 fprintf_unfiltered (gdb_stdlog
,
2927 "LLW: Re-adding thread group leader LWP %d.\n",
2930 lp
= add_lwp (ptid_build (lwpid
, lwpid
, 0));
2933 add_thread (lp
->ptid
);
2936 if (WIFSTOPPED (status
) && !lp
)
2938 if (debug_linux_nat
)
2939 fprintf_unfiltered (gdb_stdlog
,
2940 "LHEW: saving LWP %ld status %s in stopped_pids list\n",
2941 (long) lwpid
, status_to_str (status
));
2942 add_to_pid_list (&stopped_pids
, lwpid
, status
);
2946 /* Make sure we don't report an event for the exit of an LWP not in
2947 our list, i.e. not part of the current process. This can happen
2948 if we detach from a program we originally forked and then it
2950 if (!WIFSTOPPED (status
) && !lp
)
2953 /* This LWP is stopped now. (And if dead, this prevents it from
2954 ever being continued.) */
2957 if (WIFSTOPPED (status
) && lp
->must_set_ptrace_flags
)
2959 struct inferior
*inf
= find_inferior_pid (ptid_get_pid (lp
->ptid
));
2960 int options
= linux_nat_ptrace_options (inf
->attach_flag
);
2962 linux_enable_event_reporting (ptid_get_lwp (lp
->ptid
), options
);
2963 lp
->must_set_ptrace_flags
= 0;
2966 /* Handle GNU/Linux's syscall SIGTRAPs. */
2967 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SYSCALL_SIGTRAP
)
2969 /* No longer need the sysgood bit. The ptrace event ends up
2970 recorded in lp->waitstatus if we care for it. We can carry
2971 on handling the event like a regular SIGTRAP from here
2973 status
= W_STOPCODE (SIGTRAP
);
2974 if (linux_handle_syscall_trap (lp
, 0))
2979 /* Almost all other ptrace-stops are known to be outside of system
2980 calls, with further exceptions in linux_handle_extended_wait. */
2981 lp
->syscall_state
= TARGET_WAITKIND_IGNORE
;
2984 /* Handle GNU/Linux's extended waitstatus for trace events. */
2985 if (WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGTRAP
2986 && linux_is_extended_waitstatus (status
))
2988 if (debug_linux_nat
)
2989 fprintf_unfiltered (gdb_stdlog
,
2990 "LLW: Handling extended status 0x%06x\n",
2992 if (linux_handle_extended_wait (lp
, status
))
2996 /* Check if the thread has exited. */
2997 if (WIFEXITED (status
) || WIFSIGNALED (status
))
2999 if (!report_thread_events
3000 && num_lwps (ptid_get_pid (lp
->ptid
)) > 1)
3002 if (debug_linux_nat
)
3003 fprintf_unfiltered (gdb_stdlog
,
3004 "LLW: %s exited.\n",
3005 target_pid_to_str (lp
->ptid
));
3007 /* If there is at least one more LWP, then the exit signal
3008 was not the end of the debugged application and should be
3014 /* Note that even if the leader was ptrace-stopped, it can still
3015 exit, if e.g., some other thread brings down the whole
3016 process (calls `exit'). So don't assert that the lwp is
3018 if (debug_linux_nat
)
3019 fprintf_unfiltered (gdb_stdlog
,
3020 "LWP %ld exited (resumed=%d)\n",
3021 ptid_get_lwp (lp
->ptid
), lp
->resumed
);
3023 /* Dead LWP's aren't expected to reported a pending sigstop. */
3026 /* Store the pending event in the waitstatus, because
3027 W_EXITCODE(0,0) == 0. */
3028 store_waitstatus (&lp
->waitstatus
, status
);
3032 /* Make sure we don't report a SIGSTOP that we sent ourselves in
3033 an attempt to stop an LWP. */
3035 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGSTOP
)
3039 if (lp
->last_resume_kind
== resume_stop
)
3041 if (debug_linux_nat
)
3042 fprintf_unfiltered (gdb_stdlog
,
3043 "LLW: resume_stop SIGSTOP caught for %s.\n",
3044 target_pid_to_str (lp
->ptid
));
3048 /* This is a delayed SIGSTOP. Filter out the event. */
3050 if (debug_linux_nat
)
3051 fprintf_unfiltered (gdb_stdlog
,
3052 "LLW: %s %s, 0, 0 (discard delayed SIGSTOP)\n",
3054 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3055 target_pid_to_str (lp
->ptid
));
3057 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3058 gdb_assert (lp
->resumed
);
3063 /* Make sure we don't report a SIGINT that we have already displayed
3064 for another thread. */
3065 if (lp
->ignore_sigint
3066 && WIFSTOPPED (status
) && WSTOPSIG (status
) == SIGINT
)
3068 if (debug_linux_nat
)
3069 fprintf_unfiltered (gdb_stdlog
,
3070 "LLW: Delayed SIGINT caught for %s.\n",
3071 target_pid_to_str (lp
->ptid
));
3073 /* This is a delayed SIGINT. */
3074 lp
->ignore_sigint
= 0;
3076 linux_resume_one_lwp (lp
, lp
->step
, GDB_SIGNAL_0
);
3077 if (debug_linux_nat
)
3078 fprintf_unfiltered (gdb_stdlog
,
3079 "LLW: %s %s, 0, 0 (discard SIGINT)\n",
3081 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3082 target_pid_to_str (lp
->ptid
));
3083 gdb_assert (lp
->resumed
);
3085 /* Discard the event. */
3089 /* Don't report signals that GDB isn't interested in, such as
3090 signals that are neither printed nor stopped upon. Stopping all
3091 threads can be a bit time-consuming so if we want decent
3092 performance with heavily multi-threaded programs, especially when
3093 they're using a high frequency timer, we'd better avoid it if we
3095 if (WIFSTOPPED (status
))
3097 enum gdb_signal signo
= gdb_signal_from_host (WSTOPSIG (status
));
3099 if (!target_is_non_stop_p ())
3101 /* Only do the below in all-stop, as we currently use SIGSTOP
3102 to implement target_stop (see linux_nat_stop) in
3104 if (signo
== GDB_SIGNAL_INT
&& signal_pass_state (signo
) == 0)
3106 /* If ^C/BREAK is typed at the tty/console, SIGINT gets
3107 forwarded to the entire process group, that is, all LWPs
3108 will receive it - unless they're using CLONE_THREAD to
3109 share signals. Since we only want to report it once, we
3110 mark it as ignored for all LWPs except this one. */
3111 iterate_over_lwps (pid_to_ptid (ptid_get_pid (lp
->ptid
)),
3112 set_ignore_sigint
, NULL
);
3113 lp
->ignore_sigint
= 0;
3116 maybe_clear_ignore_sigint (lp
);
3119 /* When using hardware single-step, we need to report every signal.
3120 Otherwise, signals in pass_mask may be short-circuited
3121 except signals that might be caused by a breakpoint. */
3123 && WSTOPSIG (status
) && sigismember (&pass_mask
, WSTOPSIG (status
))
3124 && !linux_wstatus_maybe_breakpoint (status
))
3126 linux_resume_one_lwp (lp
, lp
->step
, signo
);
3127 if (debug_linux_nat
)
3128 fprintf_unfiltered (gdb_stdlog
,
3129 "LLW: %s %s, %s (preempt 'handle')\n",
3131 "PTRACE_SINGLESTEP" : "PTRACE_CONT",
3132 target_pid_to_str (lp
->ptid
),
3133 (signo
!= GDB_SIGNAL_0
3134 ? strsignal (gdb_signal_to_host (signo
))
3140 /* An interesting event. */
3142 lp
->status
= status
;
3143 save_stop_reason (lp
);
3147 /* Detect zombie thread group leaders, and "exit" them. We can't reap
3148 their exits until all other threads in the group have exited. */
3151 check_zombie_leaders (void)
3153 struct inferior
*inf
;
3157 struct lwp_info
*leader_lp
;
3162 leader_lp
= find_lwp_pid (pid_to_ptid (inf
->pid
));
3163 if (leader_lp
!= NULL
3164 /* Check if there are other threads in the group, as we may
3165 have raced with the inferior simply exiting. */
3166 && num_lwps (inf
->pid
) > 1
3167 && linux_proc_pid_is_zombie (inf
->pid
))
3169 if (debug_linux_nat
)
3170 fprintf_unfiltered (gdb_stdlog
,
3171 "CZL: Thread group leader %d zombie "
3172 "(it exited, or another thread execd).\n",
3175 /* A leader zombie can mean one of two things:
3177 - It exited, and there's an exit status pending
3178 available, or only the leader exited (not the whole
3179 program). In the latter case, we can't waitpid the
3180 leader's exit status until all other threads are gone.
3182 - There are 3 or more threads in the group, and a thread
3183 other than the leader exec'd. See comments on exec
3184 events at the top of the file. We could try
3185 distinguishing the exit and exec cases, by waiting once
3186 more, and seeing if something comes out, but it doesn't
3187 sound useful. The previous leader _does_ go away, and
3188 we'll re-add the new one once we see the exec event
3189 (which is just the same as what would happen if the
3190 previous leader did exit voluntarily before some other
3193 if (debug_linux_nat
)
3194 fprintf_unfiltered (gdb_stdlog
,
3195 "CZL: Thread group leader %d vanished.\n",
3197 exit_lwp (leader_lp
);
3202 /* Convenience function that is called when the kernel reports an exit
3203 event. This decides whether to report the event to GDB as a
3204 process exit event, a thread exit event, or to suppress the
3208 filter_exit_event (struct lwp_info
*event_child
,
3209 struct target_waitstatus
*ourstatus
)
3211 ptid_t ptid
= event_child
->ptid
;
3213 if (num_lwps (ptid_get_pid (ptid
)) > 1)
3215 if (report_thread_events
)
3216 ourstatus
->kind
= TARGET_WAITKIND_THREAD_EXITED
;
3218 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3220 exit_lwp (event_child
);
3227 linux_nat_wait_1 (struct target_ops
*ops
,
3228 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3232 enum resume_kind last_resume_kind
;
3233 struct lwp_info
*lp
;
3236 if (debug_linux_nat
)
3237 fprintf_unfiltered (gdb_stdlog
, "LLW: enter\n");
3239 /* The first time we get here after starting a new inferior, we may
3240 not have added it to the LWP list yet - this is the earliest
3241 moment at which we know its PID. */
3242 if (ptid_is_pid (inferior_ptid
))
3244 /* Upgrade the main thread's ptid. */
3245 thread_change_ptid (inferior_ptid
,
3246 ptid_build (ptid_get_pid (inferior_ptid
),
3247 ptid_get_pid (inferior_ptid
), 0));
3249 lp
= add_initial_lwp (inferior_ptid
);
3253 /* Make sure SIGCHLD is blocked until the sigsuspend below. */
3254 block_child_signals (&prev_mask
);
3256 /* First check if there is a LWP with a wait status pending. */
3257 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3260 if (debug_linux_nat
)
3261 fprintf_unfiltered (gdb_stdlog
,
3262 "LLW: Using pending wait status %s for %s.\n",
3263 status_to_str (lp
->status
),
3264 target_pid_to_str (lp
->ptid
));
3267 /* But if we don't find a pending event, we'll have to wait. Always
3268 pull all events out of the kernel. We'll randomly select an
3269 event LWP out of all that have events, to prevent starvation. */
3275 /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace
3278 - If the thread group leader exits while other threads in the
3279 thread group still exist, waitpid(TGID, ...) hangs. That
3280 waitpid won't return an exit status until the other threads
3281 in the group are reapped.
3283 - When a non-leader thread execs, that thread just vanishes
3284 without reporting an exit (so we'd hang if we waited for it
3285 explicitly in that case). The exec event is reported to
3289 lwpid
= my_waitpid (-1, &status
, __WALL
| WNOHANG
);
3291 if (debug_linux_nat
)
3292 fprintf_unfiltered (gdb_stdlog
,
3293 "LNW: waitpid(-1, ...) returned %d, %s\n",
3294 lwpid
, errno
? safe_strerror (errno
) : "ERRNO-OK");
3298 if (debug_linux_nat
)
3300 fprintf_unfiltered (gdb_stdlog
,
3301 "LLW: waitpid %ld received %s\n",
3302 (long) lwpid
, status_to_str (status
));
3305 linux_nat_filter_event (lwpid
, status
);
3306 /* Retry until nothing comes out of waitpid. A single
3307 SIGCHLD can indicate more than one child stopped. */
3311 /* Now that we've pulled all events out of the kernel, resume
3312 LWPs that don't have an interesting event to report. */
3313 iterate_over_lwps (minus_one_ptid
,
3314 resume_stopped_resumed_lwps
, &minus_one_ptid
);
3316 /* ... and find an LWP with a status to report to the core, if
3318 lp
= iterate_over_lwps (ptid
, status_callback
, NULL
);
3322 /* Check for zombie thread group leaders. Those can't be reaped
3323 until all other threads in the thread group are. */
3324 check_zombie_leaders ();
3326 /* If there are no resumed children left, bail. We'd be stuck
3327 forever in the sigsuspend call below otherwise. */
3328 if (iterate_over_lwps (ptid
, resumed_callback
, NULL
) == NULL
)
3330 if (debug_linux_nat
)
3331 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (no resumed LWP)\n");
3333 ourstatus
->kind
= TARGET_WAITKIND_NO_RESUMED
;
3335 restore_child_signals_mask (&prev_mask
);
3336 return minus_one_ptid
;
3339 /* No interesting event to report to the core. */
3341 if (target_options
& TARGET_WNOHANG
)
3343 if (debug_linux_nat
)
3344 fprintf_unfiltered (gdb_stdlog
, "LLW: exit (ignore)\n");
3346 ourstatus
->kind
= TARGET_WAITKIND_IGNORE
;
3347 restore_child_signals_mask (&prev_mask
);
3348 return minus_one_ptid
;
3351 /* We shouldn't end up here unless we want to try again. */
3352 gdb_assert (lp
== NULL
);
3354 /* Block until we get an event reported with SIGCHLD. */
3355 if (debug_linux_nat
)
3356 fprintf_unfiltered (gdb_stdlog
, "LNW: about to sigsuspend\n");
3357 sigsuspend (&suspend_mask
);
3362 status
= lp
->status
;
3365 if (!target_is_non_stop_p ())
3367 /* Now stop all other LWP's ... */
3368 iterate_over_lwps (minus_one_ptid
, stop_callback
, NULL
);
3370 /* ... and wait until all of them have reported back that
3371 they're no longer running. */
3372 iterate_over_lwps (minus_one_ptid
, stop_wait_callback
, NULL
);
3375 /* If we're not waiting for a specific LWP, choose an event LWP from
3376 among those that have had events. Giving equal priority to all
3377 LWPs that have had events helps prevent starvation. */
3378 if (ptid_equal (ptid
, minus_one_ptid
) || ptid_is_pid (ptid
))
3379 select_event_lwp (ptid
, &lp
, &status
);
3381 gdb_assert (lp
!= NULL
);
3383 /* Now that we've selected our final event LWP, un-adjust its PC if
3384 it was a software breakpoint, and we can't reliably support the
3385 "stopped by software breakpoint" stop reason. */
3386 if (lp
->stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3387 && !USE_SIGTRAP_SIGINFO
)
3389 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3390 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3391 int decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3397 pc
= regcache_read_pc (regcache
);
3398 regcache_write_pc (regcache
, pc
+ decr_pc
);
3402 /* We'll need this to determine whether to report a SIGSTOP as
3403 GDB_SIGNAL_0. Need to take a copy because resume_clear_callback
3405 last_resume_kind
= lp
->last_resume_kind
;
3407 if (!target_is_non_stop_p ())
3409 /* In all-stop, from the core's perspective, all LWPs are now
3410 stopped until a new resume action is sent over. */
3411 iterate_over_lwps (minus_one_ptid
, resume_clear_callback
, NULL
);
3415 resume_clear_callback (lp
, NULL
);
3418 if (linux_nat_status_is_event (status
))
3420 if (debug_linux_nat
)
3421 fprintf_unfiltered (gdb_stdlog
,
3422 "LLW: trap ptid is %s.\n",
3423 target_pid_to_str (lp
->ptid
));
3426 if (lp
->waitstatus
.kind
!= TARGET_WAITKIND_IGNORE
)
3428 *ourstatus
= lp
->waitstatus
;
3429 lp
->waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
3432 store_waitstatus (ourstatus
, status
);
3434 if (debug_linux_nat
)
3435 fprintf_unfiltered (gdb_stdlog
, "LLW: exit\n");
3437 restore_child_signals_mask (&prev_mask
);
3439 if (last_resume_kind
== resume_stop
3440 && ourstatus
->kind
== TARGET_WAITKIND_STOPPED
3441 && WSTOPSIG (status
) == SIGSTOP
)
3443 /* A thread that has been requested to stop by GDB with
3444 target_stop, and it stopped cleanly, so report as SIG0. The
3445 use of SIGSTOP is an implementation detail. */
3446 ourstatus
->value
.sig
= GDB_SIGNAL_0
;
3449 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
3450 || ourstatus
->kind
== TARGET_WAITKIND_SIGNALLED
)
3453 lp
->core
= linux_common_core_of_thread (lp
->ptid
);
3455 if (ourstatus
->kind
== TARGET_WAITKIND_EXITED
)
3456 return filter_exit_event (lp
, ourstatus
);
3461 /* Resume LWPs that are currently stopped without any pending status
3462 to report, but are resumed from the core's perspective. */
3465 resume_stopped_resumed_lwps (struct lwp_info
*lp
, void *data
)
3467 ptid_t
*wait_ptid_p
= (ptid_t
*) data
;
3471 if (debug_linux_nat
)
3472 fprintf_unfiltered (gdb_stdlog
,
3473 "RSRL: NOT resuming LWP %s, not stopped\n",
3474 target_pid_to_str (lp
->ptid
));
3476 else if (!lp
->resumed
)
3478 if (debug_linux_nat
)
3479 fprintf_unfiltered (gdb_stdlog
,
3480 "RSRL: NOT resuming LWP %s, not resumed\n",
3481 target_pid_to_str (lp
->ptid
));
3483 else if (lwp_status_pending_p (lp
))
3485 if (debug_linux_nat
)
3486 fprintf_unfiltered (gdb_stdlog
,
3487 "RSRL: NOT resuming LWP %s, has pending status\n",
3488 target_pid_to_str (lp
->ptid
));
3492 struct regcache
*regcache
= get_thread_regcache (lp
->ptid
);
3493 struct gdbarch
*gdbarch
= get_regcache_arch (regcache
);
3497 CORE_ADDR pc
= regcache_read_pc (regcache
);
3498 int leave_stopped
= 0;
3500 /* Don't bother if there's a breakpoint at PC that we'd hit
3501 immediately, and we're not waiting for this LWP. */
3502 if (!ptid_match (lp
->ptid
, *wait_ptid_p
))
3504 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache
), pc
))
3510 if (debug_linux_nat
)
3511 fprintf_unfiltered (gdb_stdlog
,
3512 "RSRL: resuming stopped-resumed LWP %s at "
3514 target_pid_to_str (lp
->ptid
),
3515 paddress (gdbarch
, pc
),
3518 linux_resume_one_lwp_throw (lp
, lp
->step
, GDB_SIGNAL_0
);
3521 CATCH (ex
, RETURN_MASK_ERROR
)
3523 if (!check_ptrace_stopped_lwp_gone (lp
))
3524 throw_exception (ex
);
3533 linux_nat_wait (struct target_ops
*ops
,
3534 ptid_t ptid
, struct target_waitstatus
*ourstatus
,
3539 if (debug_linux_nat
)
3541 char *options_string
;
3543 options_string
= target_options_to_string (target_options
);
3544 fprintf_unfiltered (gdb_stdlog
,
3545 "linux_nat_wait: [%s], [%s]\n",
3546 target_pid_to_str (ptid
),
3548 xfree (options_string
);
3551 /* Flush the async file first. */
3552 if (target_is_async_p ())
3553 async_file_flush ();
3555 /* Resume LWPs that are currently stopped without any pending status
3556 to report, but are resumed from the core's perspective. LWPs get
3557 in this state if we find them stopping at a time we're not
3558 interested in reporting the event (target_wait on a
3559 specific_process, for example, see linux_nat_wait_1), and
3560 meanwhile the event became uninteresting. Don't bother resuming
3561 LWPs we're not going to wait for if they'd stop immediately. */
3562 if (target_is_non_stop_p ())
3563 iterate_over_lwps (minus_one_ptid
, resume_stopped_resumed_lwps
, &ptid
);
3565 event_ptid
= linux_nat_wait_1 (ops
, ptid
, ourstatus
, target_options
);
3567 /* If we requested any event, and something came out, assume there
3568 may be more. If we requested a specific lwp or process, also
3569 assume there may be more. */
3570 if (target_is_async_p ()
3571 && ((ourstatus
->kind
!= TARGET_WAITKIND_IGNORE
3572 && ourstatus
->kind
!= TARGET_WAITKIND_NO_RESUMED
)
3573 || !ptid_equal (ptid
, minus_one_ptid
)))
3582 kill_one_lwp (pid_t pid
)
3584 /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */
3587 kill_lwp (pid
, SIGKILL
);
3588 if (debug_linux_nat
)
3590 int save_errno
= errno
;
3592 fprintf_unfiltered (gdb_stdlog
,
3593 "KC: kill (SIGKILL) %ld, 0, 0 (%s)\n", (long) pid
,
3594 save_errno
? safe_strerror (save_errno
) : "OK");
3597 /* Some kernels ignore even SIGKILL for processes under ptrace. */
3600 ptrace (PTRACE_KILL
, pid
, 0, 0);
3601 if (debug_linux_nat
)
3603 int save_errno
= errno
;
3605 fprintf_unfiltered (gdb_stdlog
,
3606 "KC: PTRACE_KILL %ld, 0, 0 (%s)\n", (long) pid
,
3607 save_errno
? safe_strerror (save_errno
) : "OK");
3611 /* Wait for an LWP to die. */
3614 kill_wait_one_lwp (pid_t pid
)
3618 /* We must make sure that there are no pending events (delayed
3619 SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current
3620 program doesn't interfere with any following debugging session. */
3624 res
= my_waitpid (pid
, NULL
, __WALL
);
3625 if (res
!= (pid_t
) -1)
3627 if (debug_linux_nat
)
3628 fprintf_unfiltered (gdb_stdlog
,
3629 "KWC: wait %ld received unknown.\n",
3631 /* The Linux kernel sometimes fails to kill a thread
3632 completely after PTRACE_KILL; that goes from the stop
3633 point in do_fork out to the one in get_signal_to_deliver
3634 and waits again. So kill it again. */
3640 gdb_assert (res
== -1 && errno
== ECHILD
);
3643 /* Callback for iterate_over_lwps. */
3646 kill_callback (struct lwp_info
*lp
, void *data
)
3648 kill_one_lwp (ptid_get_lwp (lp
->ptid
));
3652 /* Callback for iterate_over_lwps. */
3655 kill_wait_callback (struct lwp_info
*lp
, void *data
)
3657 kill_wait_one_lwp (ptid_get_lwp (lp
->ptid
));
3661 /* Kill the fork children of any threads of inferior INF that are
3662 stopped at a fork event. */
3665 kill_unfollowed_fork_children (struct inferior
*inf
)
3667 struct thread_info
*thread
;
3669 ALL_NON_EXITED_THREADS (thread
)
3670 if (thread
->inf
== inf
)
3672 struct target_waitstatus
*ws
= &thread
->pending_follow
;
3674 if (ws
->kind
== TARGET_WAITKIND_FORKED
3675 || ws
->kind
== TARGET_WAITKIND_VFORKED
)
3677 ptid_t child_ptid
= ws
->value
.related_pid
;
3678 int child_pid
= ptid_get_pid (child_ptid
);
3679 int child_lwp
= ptid_get_lwp (child_ptid
);
3681 kill_one_lwp (child_lwp
);
3682 kill_wait_one_lwp (child_lwp
);
3684 /* Let the arch-specific native code know this process is
3686 linux_nat_forget_process (child_pid
);
3692 linux_nat_kill (struct target_ops
*ops
)
3694 /* If we're stopped while forking and we haven't followed yet,
3695 kill the other task. We need to do this first because the
3696 parent will be sleeping if this is a vfork. */
3697 kill_unfollowed_fork_children (current_inferior ());
3699 if (forks_exist_p ())
3700 linux_fork_killall ();
3703 ptid_t ptid
= pid_to_ptid (ptid_get_pid (inferior_ptid
));
3705 /* Stop all threads before killing them, since ptrace requires
3706 that the thread is stopped to sucessfully PTRACE_KILL. */
3707 iterate_over_lwps (ptid
, stop_callback
, NULL
);
3708 /* ... and wait until all of them have reported back that
3709 they're no longer running. */
3710 iterate_over_lwps (ptid
, stop_wait_callback
, NULL
);
3712 /* Kill all LWP's ... */
3713 iterate_over_lwps (ptid
, kill_callback
, NULL
);
3715 /* ... and wait until we've flushed all events. */
3716 iterate_over_lwps (ptid
, kill_wait_callback
, NULL
);
3719 target_mourn_inferior ();
3723 linux_nat_mourn_inferior (struct target_ops
*ops
)
3725 int pid
= ptid_get_pid (inferior_ptid
);
3727 purge_lwp_list (pid
);
3729 if (! forks_exist_p ())
3730 /* Normal case, no other forks available. */
3731 linux_ops
->to_mourn_inferior (ops
);
3733 /* Multi-fork case. The current inferior_ptid has exited, but
3734 there are other viable forks to debug. Delete the exiting
3735 one and context-switch to the first available. */
3736 linux_fork_mourn_inferior ();
3738 /* Let the arch-specific native code know this process is gone. */
3739 linux_nat_forget_process (pid
);
3742 /* Convert a native/host siginfo object, into/from the siginfo in the
3743 layout of the inferiors' architecture. */
3746 siginfo_fixup (siginfo_t
*siginfo
, gdb_byte
*inf_siginfo
, int direction
)
3750 if (linux_nat_siginfo_fixup
!= NULL
)
3751 done
= linux_nat_siginfo_fixup (siginfo
, inf_siginfo
, direction
);
3753 /* If there was no callback, or the callback didn't do anything,
3754 then just do a straight memcpy. */
3758 memcpy (siginfo
, inf_siginfo
, sizeof (siginfo_t
));
3760 memcpy (inf_siginfo
, siginfo
, sizeof (siginfo_t
));
3764 static enum target_xfer_status
3765 linux_xfer_siginfo (struct target_ops
*ops
, enum target_object object
,
3766 const char *annex
, gdb_byte
*readbuf
,
3767 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
3768 ULONGEST
*xfered_len
)
3772 gdb_byte inf_siginfo
[sizeof (siginfo_t
)];
3774 gdb_assert (object
== TARGET_OBJECT_SIGNAL_INFO
);
3775 gdb_assert (readbuf
|| writebuf
);
3777 pid
= ptid_get_lwp (inferior_ptid
);
3779 pid
= ptid_get_pid (inferior_ptid
);
3781 if (offset
> sizeof (siginfo
))
3782 return TARGET_XFER_E_IO
;
3785 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3787 return TARGET_XFER_E_IO
;
3789 /* When GDB is built as a 64-bit application, ptrace writes into
3790 SIGINFO an object with 64-bit layout. Since debugging a 32-bit
3791 inferior with a 64-bit GDB should look the same as debugging it
3792 with a 32-bit GDB, we need to convert it. GDB core always sees
3793 the converted layout, so any read/write will have to be done
3795 siginfo_fixup (&siginfo
, inf_siginfo
, 0);
3797 if (offset
+ len
> sizeof (siginfo
))
3798 len
= sizeof (siginfo
) - offset
;
3800 if (readbuf
!= NULL
)
3801 memcpy (readbuf
, inf_siginfo
+ offset
, len
);
3804 memcpy (inf_siginfo
+ offset
, writebuf
, len
);
3806 /* Convert back to ptrace layout before flushing it out. */
3807 siginfo_fixup (&siginfo
, inf_siginfo
, 1);
3810 ptrace (PTRACE_SETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, &siginfo
);
3812 return TARGET_XFER_E_IO
;
3816 return TARGET_XFER_OK
;
3819 static enum target_xfer_status
3820 linux_nat_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3821 const char *annex
, gdb_byte
*readbuf
,
3822 const gdb_byte
*writebuf
,
3823 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
3825 struct cleanup
*old_chain
;
3826 enum target_xfer_status xfer
;
3828 if (object
== TARGET_OBJECT_SIGNAL_INFO
)
3829 return linux_xfer_siginfo (ops
, object
, annex
, readbuf
, writebuf
,
3830 offset
, len
, xfered_len
);
3832 /* The target is connected but no live inferior is selected. Pass
3833 this request down to a lower stratum (e.g., the executable
3835 if (object
== TARGET_OBJECT_MEMORY
&& ptid_equal (inferior_ptid
, null_ptid
))
3836 return TARGET_XFER_EOF
;
3838 old_chain
= save_inferior_ptid ();
3840 if (ptid_lwp_p (inferior_ptid
))
3841 inferior_ptid
= pid_to_ptid (ptid_get_lwp (inferior_ptid
));
3843 xfer
= linux_ops
->to_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
3844 offset
, len
, xfered_len
);
3846 do_cleanups (old_chain
);
3851 linux_nat_thread_alive (struct target_ops
*ops
, ptid_t ptid
)
3853 /* As long as a PTID is in lwp list, consider it alive. */
3854 return find_lwp_pid (ptid
) != NULL
;
3857 /* Implement the to_update_thread_list target method for this
3861 linux_nat_update_thread_list (struct target_ops
*ops
)
3863 struct lwp_info
*lwp
;
3865 /* We add/delete threads from the list as clone/exit events are
3866 processed, so just try deleting exited threads still in the
3868 delete_exited_threads ();
3870 /* Update the processor core that each lwp/thread was last seen
3874 /* Avoid accessing /proc if the thread hasn't run since we last
3875 time we fetched the thread's core. Accessing /proc becomes
3876 noticeably expensive when we have thousands of LWPs. */
3877 if (lwp
->core
== -1)
3878 lwp
->core
= linux_common_core_of_thread (lwp
->ptid
);
3883 linux_nat_pid_to_str (struct target_ops
*ops
, ptid_t ptid
)
3885 static char buf
[64];
3887 if (ptid_lwp_p (ptid
)
3888 && (ptid_get_pid (ptid
) != ptid_get_lwp (ptid
)
3889 || num_lwps (ptid_get_pid (ptid
)) > 1))
3891 snprintf (buf
, sizeof (buf
), "LWP %ld", ptid_get_lwp (ptid
));
3895 return normal_pid_to_str (ptid
);
3899 linux_nat_thread_name (struct target_ops
*self
, struct thread_info
*thr
)
3901 return linux_proc_tid_get_name (thr
->ptid
);
3904 /* Accepts an integer PID; Returns a string representing a file that
3905 can be opened to get the symbols for the child process. */
3908 linux_child_pid_to_exec_file (struct target_ops
*self
, int pid
)
3910 return linux_proc_pid_to_exec_file (pid
);
3913 /* Implement the to_xfer_partial interface for memory reads using the /proc
3914 filesystem. Because we can use a single read() call for /proc, this
3915 can be much more efficient than banging away at PTRACE_PEEKTEXT,
3916 but it doesn't support writes. */
3918 static enum target_xfer_status
3919 linux_proc_xfer_partial (struct target_ops
*ops
, enum target_object object
,
3920 const char *annex
, gdb_byte
*readbuf
,
3921 const gdb_byte
*writebuf
,
3922 ULONGEST offset
, LONGEST len
, ULONGEST
*xfered_len
)
3928 if (object
!= TARGET_OBJECT_MEMORY
|| !readbuf
)
3929 return TARGET_XFER_EOF
;
3931 /* Don't bother for one word. */
3932 if (len
< 3 * sizeof (long))
3933 return TARGET_XFER_EOF
;
3935 /* We could keep this file open and cache it - possibly one per
3936 thread. That requires some juggling, but is even faster. */
3937 xsnprintf (filename
, sizeof filename
, "/proc/%d/mem",
3938 ptid_get_pid (inferior_ptid
));
3939 fd
= gdb_open_cloexec (filename
, O_RDONLY
| O_LARGEFILE
, 0);
3941 return TARGET_XFER_EOF
;
3943 /* If pread64 is available, use it. It's faster if the kernel
3944 supports it (only one syscall), and it's 64-bit safe even on
3945 32-bit platforms (for instance, SPARC debugging a SPARC64
3948 if (pread64 (fd
, readbuf
, len
, offset
) != len
)
3950 if (lseek (fd
, offset
, SEEK_SET
) == -1 || read (fd
, readbuf
, len
) != len
)
3959 return TARGET_XFER_EOF
;
3963 return TARGET_XFER_OK
;
3968 /* Enumerate spufs IDs for process PID. */
3970 spu_enumerate_spu_ids (int pid
, gdb_byte
*buf
, ULONGEST offset
, ULONGEST len
)
3972 enum bfd_endian byte_order
= gdbarch_byte_order (target_gdbarch ());
3974 LONGEST written
= 0;
3977 struct dirent
*entry
;
3979 xsnprintf (path
, sizeof path
, "/proc/%d/fd", pid
);
3980 dir
= opendir (path
);
3985 while ((entry
= readdir (dir
)) != NULL
)
3991 fd
= atoi (entry
->d_name
);
3995 xsnprintf (path
, sizeof path
, "/proc/%d/fd/%d", pid
, fd
);
3996 if (stat (path
, &st
) != 0)
3998 if (!S_ISDIR (st
.st_mode
))
4001 if (statfs (path
, &stfs
) != 0)
4003 if (stfs
.f_type
!= SPUFS_MAGIC
)
4006 if (pos
>= offset
&& pos
+ 4 <= offset
+ len
)
4008 store_unsigned_integer (buf
+ pos
- offset
, 4, byte_order
, fd
);
4018 /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU
4019 object type, using the /proc file system. */
4021 static enum target_xfer_status
4022 linux_proc_xfer_spu (struct target_ops
*ops
, enum target_object object
,
4023 const char *annex
, gdb_byte
*readbuf
,
4024 const gdb_byte
*writebuf
,
4025 ULONGEST offset
, ULONGEST len
, ULONGEST
*xfered_len
)
4030 int pid
= ptid_get_pid (inferior_ptid
);
4035 return TARGET_XFER_E_IO
;
4038 LONGEST l
= spu_enumerate_spu_ids (pid
, readbuf
, offset
, len
);
4041 return TARGET_XFER_E_IO
;
4043 return TARGET_XFER_EOF
;
4046 *xfered_len
= (ULONGEST
) l
;
4047 return TARGET_XFER_OK
;
4052 xsnprintf (buf
, sizeof buf
, "/proc/%d/fd/%s", pid
, annex
);
4053 fd
= gdb_open_cloexec (buf
, writebuf
? O_WRONLY
: O_RDONLY
, 0);
4055 return TARGET_XFER_E_IO
;
4058 && lseek (fd
, (off_t
) offset
, SEEK_SET
) != (off_t
) offset
)
4061 return TARGET_XFER_EOF
;
4065 ret
= write (fd
, writebuf
, (size_t) len
);
4067 ret
= read (fd
, readbuf
, (size_t) len
);
4072 return TARGET_XFER_E_IO
;
4074 return TARGET_XFER_EOF
;
4077 *xfered_len
= (ULONGEST
) ret
;
4078 return TARGET_XFER_OK
;
4083 /* Parse LINE as a signal set and add its set bits to SIGS. */
4086 add_line_to_sigset (const char *line
, sigset_t
*sigs
)
4088 int len
= strlen (line
) - 1;
4092 if (line
[len
] != '\n')
4093 error (_("Could not parse signal set: %s"), line
);
4101 if (*p
>= '0' && *p
<= '9')
4103 else if (*p
>= 'a' && *p
<= 'f')
4104 digit
= *p
- 'a' + 10;
4106 error (_("Could not parse signal set: %s"), line
);
4111 sigaddset (sigs
, signum
+ 1);
4113 sigaddset (sigs
, signum
+ 2);
4115 sigaddset (sigs
, signum
+ 3);
4117 sigaddset (sigs
, signum
+ 4);
4123 /* Find process PID's pending signals from /proc/pid/status and set
4127 linux_proc_pending_signals (int pid
, sigset_t
*pending
,
4128 sigset_t
*blocked
, sigset_t
*ignored
)
4131 char buffer
[PATH_MAX
], fname
[PATH_MAX
];
4132 struct cleanup
*cleanup
;
4134 sigemptyset (pending
);
4135 sigemptyset (blocked
);
4136 sigemptyset (ignored
);
4137 xsnprintf (fname
, sizeof fname
, "/proc/%d/status", pid
);
4138 procfile
= gdb_fopen_cloexec (fname
, "r");
4139 if (procfile
== NULL
)
4140 error (_("Could not open %s"), fname
);
4141 cleanup
= make_cleanup_fclose (procfile
);
4143 while (fgets (buffer
, PATH_MAX
, procfile
) != NULL
)
4145 /* Normal queued signals are on the SigPnd line in the status
4146 file. However, 2.6 kernels also have a "shared" pending
4147 queue for delivering signals to a thread group, so check for
4150 Unfortunately some Red Hat kernels include the shared pending
4151 queue but not the ShdPnd status field. */
4153 if (startswith (buffer
, "SigPnd:\t"))
4154 add_line_to_sigset (buffer
+ 8, pending
);
4155 else if (startswith (buffer
, "ShdPnd:\t"))
4156 add_line_to_sigset (buffer
+ 8, pending
);
4157 else if (startswith (buffer
, "SigBlk:\t"))
4158 add_line_to_sigset (buffer
+ 8, blocked
);
4159 else if (startswith (buffer
, "SigIgn:\t"))
4160 add_line_to_sigset (buffer
+ 8, ignored
);
4163 do_cleanups (cleanup
);
4166 static enum target_xfer_status
4167 linux_nat_xfer_osdata (struct target_ops
*ops
, enum target_object object
,
4168 const char *annex
, gdb_byte
*readbuf
,
4169 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4170 ULONGEST
*xfered_len
)
4172 gdb_assert (object
== TARGET_OBJECT_OSDATA
);
4174 *xfered_len
= linux_common_xfer_osdata (annex
, readbuf
, offset
, len
);
4175 if (*xfered_len
== 0)
4176 return TARGET_XFER_EOF
;
4178 return TARGET_XFER_OK
;
4181 static enum target_xfer_status
4182 linux_xfer_partial (struct target_ops
*ops
, enum target_object object
,
4183 const char *annex
, gdb_byte
*readbuf
,
4184 const gdb_byte
*writebuf
, ULONGEST offset
, ULONGEST len
,
4185 ULONGEST
*xfered_len
)
4187 enum target_xfer_status xfer
;
4189 if (object
== TARGET_OBJECT_AUXV
)
4190 return memory_xfer_auxv (ops
, object
, annex
, readbuf
, writebuf
,
4191 offset
, len
, xfered_len
);
4193 if (object
== TARGET_OBJECT_OSDATA
)
4194 return linux_nat_xfer_osdata (ops
, object
, annex
, readbuf
, writebuf
,
4195 offset
, len
, xfered_len
);
4197 if (object
== TARGET_OBJECT_SPU
)
4198 return linux_proc_xfer_spu (ops
, object
, annex
, readbuf
, writebuf
,
4199 offset
, len
, xfered_len
);
4201 /* GDB calculates all the addresses in possibly larget width of the address.
4202 Address width needs to be masked before its final use - either by
4203 linux_proc_xfer_partial or inf_ptrace_xfer_partial.
4205 Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */
4207 if (object
== TARGET_OBJECT_MEMORY
)
4209 int addr_bit
= gdbarch_addr_bit (target_gdbarch ());
4211 if (addr_bit
< (sizeof (ULONGEST
) * HOST_CHAR_BIT
))
4212 offset
&= ((ULONGEST
) 1 << addr_bit
) - 1;
4215 xfer
= linux_proc_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4216 offset
, len
, xfered_len
);
4217 if (xfer
!= TARGET_XFER_EOF
)
4220 return super_xfer_partial (ops
, object
, annex
, readbuf
, writebuf
,
4221 offset
, len
, xfered_len
);
4225 cleanup_target_stop (void *arg
)
4227 ptid_t
*ptid
= (ptid_t
*) arg
;
4229 gdb_assert (arg
!= NULL
);
4232 target_resume (*ptid
, 0, GDB_SIGNAL_0
);
4235 static VEC(static_tracepoint_marker_p
) *
4236 linux_child_static_tracepoint_markers_by_strid (struct target_ops
*self
,
4239 char s
[IPA_CMD_BUF_SIZE
];
4240 struct cleanup
*old_chain
;
4241 int pid
= ptid_get_pid (inferior_ptid
);
4242 VEC(static_tracepoint_marker_p
) *markers
= NULL
;
4243 struct static_tracepoint_marker
*marker
= NULL
;
4245 ptid_t ptid
= ptid_build (pid
, 0, 0);
4250 memcpy (s
, "qTfSTM", sizeof ("qTfSTM"));
4251 s
[sizeof ("qTfSTM")] = 0;
4253 agent_run_command (pid
, s
, strlen (s
) + 1);
4255 old_chain
= make_cleanup (free_current_marker
, &marker
);
4256 make_cleanup (cleanup_target_stop
, &ptid
);
4261 marker
= XCNEW (struct static_tracepoint_marker
);
4265 parse_static_tracepoint_marker_definition (p
, &p
, marker
);
4267 if (strid
== NULL
|| strcmp (strid
, marker
->str_id
) == 0)
4269 VEC_safe_push (static_tracepoint_marker_p
,
4275 release_static_tracepoint_marker (marker
);
4276 memset (marker
, 0, sizeof (*marker
));
4279 while (*p
++ == ','); /* comma-separated list */
4281 memcpy (s
, "qTsSTM", sizeof ("qTsSTM"));
4282 s
[sizeof ("qTsSTM")] = 0;
4283 agent_run_command (pid
, s
, strlen (s
) + 1);
4287 do_cleanups (old_chain
);
4292 /* Create a prototype generic GNU/Linux target. The client can override
4293 it with local methods. */
4296 linux_target_install_ops (struct target_ops
*t
)
4298 t
->to_insert_fork_catchpoint
= linux_child_insert_fork_catchpoint
;
4299 t
->to_remove_fork_catchpoint
= linux_child_remove_fork_catchpoint
;
4300 t
->to_insert_vfork_catchpoint
= linux_child_insert_vfork_catchpoint
;
4301 t
->to_remove_vfork_catchpoint
= linux_child_remove_vfork_catchpoint
;
4302 t
->to_insert_exec_catchpoint
= linux_child_insert_exec_catchpoint
;
4303 t
->to_remove_exec_catchpoint
= linux_child_remove_exec_catchpoint
;
4304 t
->to_set_syscall_catchpoint
= linux_child_set_syscall_catchpoint
;
4305 t
->to_pid_to_exec_file
= linux_child_pid_to_exec_file
;
4306 t
->to_post_startup_inferior
= linux_child_post_startup_inferior
;
4307 t
->to_post_attach
= linux_child_post_attach
;
4308 t
->to_follow_fork
= linux_child_follow_fork
;
4310 super_xfer_partial
= t
->to_xfer_partial
;
4311 t
->to_xfer_partial
= linux_xfer_partial
;
4313 t
->to_static_tracepoint_markers_by_strid
4314 = linux_child_static_tracepoint_markers_by_strid
;
4320 struct target_ops
*t
;
4322 t
= inf_ptrace_target ();
4323 linux_target_install_ops (t
);
4329 linux_trad_target (CORE_ADDR (*register_u_offset
)(struct gdbarch
*, int, int))
4331 struct target_ops
*t
;
4333 t
= inf_ptrace_trad_target (register_u_offset
);
4334 linux_target_install_ops (t
);
4339 /* target_is_async_p implementation. */
4342 linux_nat_is_async_p (struct target_ops
*ops
)
4344 return linux_is_async_p ();
4347 /* target_can_async_p implementation. */
4350 linux_nat_can_async_p (struct target_ops
*ops
)
4352 /* NOTE: palves 2008-03-21: We're only async when the user requests
4353 it explicitly with the "set target-async" command.
4354 Someday, linux will always be async. */
4355 return target_async_permitted
;
4359 linux_nat_supports_non_stop (struct target_ops
*self
)
4364 /* to_always_non_stop_p implementation. */
4367 linux_nat_always_non_stop_p (struct target_ops
*self
)
4372 /* True if we want to support multi-process. To be removed when GDB
4373 supports multi-exec. */
4375 int linux_multi_process
= 1;
4378 linux_nat_supports_multi_process (struct target_ops
*self
)
4380 return linux_multi_process
;
4384 linux_nat_supports_disable_randomization (struct target_ops
*self
)
4386 #ifdef HAVE_PERSONALITY
4393 static int async_terminal_is_ours
= 1;
4395 /* target_terminal_inferior implementation.
4397 This is a wrapper around child_terminal_inferior to add async support. */
4400 linux_nat_terminal_inferior (struct target_ops
*self
)
4402 child_terminal_inferior (self
);
4404 /* Calls to target_terminal_*() are meant to be idempotent. */
4405 if (!async_terminal_is_ours
)
4408 delete_file_handler (input_fd
);
4409 async_terminal_is_ours
= 0;
4413 /* target_terminal_ours implementation.
4415 This is a wrapper around child_terminal_ours to add async support (and
4416 implement the target_terminal_ours vs target_terminal_ours_for_output
4417 distinction). child_terminal_ours is currently no different than
4418 child_terminal_ours_for_output.
4419 We leave target_terminal_ours_for_output alone, leaving it to
4420 child_terminal_ours_for_output. */
4423 linux_nat_terminal_ours (struct target_ops
*self
)
4425 /* GDB should never give the terminal to the inferior if the
4426 inferior is running in the background (run&, continue&, etc.),
4427 but claiming it sure should. */
4428 child_terminal_ours (self
);
4430 if (async_terminal_is_ours
)
4433 clear_sigint_trap ();
4434 add_file_handler (input_fd
, stdin_event_handler
, 0);
4435 async_terminal_is_ours
= 1;
4438 /* SIGCHLD handler that serves two purposes: In non-stop/async mode,
4439 so we notice when any child changes state, and notify the
4440 event-loop; it allows us to use sigsuspend in linux_nat_wait_1
4441 above to wait for the arrival of a SIGCHLD. */
4444 sigchld_handler (int signo
)
4446 int old_errno
= errno
;
4448 if (debug_linux_nat
)
4449 ui_file_write_async_safe (gdb_stdlog
,
4450 "sigchld\n", sizeof ("sigchld\n") - 1);
4452 if (signo
== SIGCHLD
4453 && linux_nat_event_pipe
[0] != -1)
4454 async_file_mark (); /* Let the event loop know that there are
4455 events to handle. */
4460 /* Callback registered with the target events file descriptor. */
4463 handle_target_event (int error
, gdb_client_data client_data
)
4465 inferior_event_handler (INF_REG_EVENT
, NULL
);
4468 /* Create/destroy the target events pipe. Returns previous state. */
4471 linux_async_pipe (int enable
)
4473 int previous
= linux_is_async_p ();
4475 if (previous
!= enable
)
4479 /* Block child signals while we create/destroy the pipe, as
4480 their handler writes to it. */
4481 block_child_signals (&prev_mask
);
4485 if (gdb_pipe_cloexec (linux_nat_event_pipe
) == -1)
4486 internal_error (__FILE__
, __LINE__
,
4487 "creating event pipe failed.");
4489 fcntl (linux_nat_event_pipe
[0], F_SETFL
, O_NONBLOCK
);
4490 fcntl (linux_nat_event_pipe
[1], F_SETFL
, O_NONBLOCK
);
4494 close (linux_nat_event_pipe
[0]);
4495 close (linux_nat_event_pipe
[1]);
4496 linux_nat_event_pipe
[0] = -1;
4497 linux_nat_event_pipe
[1] = -1;
4500 restore_child_signals_mask (&prev_mask
);
4506 /* target_async implementation. */
4509 linux_nat_async (struct target_ops
*ops
, int enable
)
4513 if (!linux_async_pipe (1))
4515 add_file_handler (linux_nat_event_pipe
[0],
4516 handle_target_event
, NULL
);
4517 /* There may be pending events to handle. Tell the event loop
4524 delete_file_handler (linux_nat_event_pipe
[0]);
4525 linux_async_pipe (0);
4530 /* Stop an LWP, and push a GDB_SIGNAL_0 stop status if no other
4534 linux_nat_stop_lwp (struct lwp_info
*lwp
, void *data
)
4538 if (debug_linux_nat
)
4539 fprintf_unfiltered (gdb_stdlog
,
4540 "LNSL: running -> suspending %s\n",
4541 target_pid_to_str (lwp
->ptid
));
4544 if (lwp
->last_resume_kind
== resume_stop
)
4546 if (debug_linux_nat
)
4547 fprintf_unfiltered (gdb_stdlog
,
4548 "linux-nat: already stopping LWP %ld at "
4550 ptid_get_lwp (lwp
->ptid
));
4554 stop_callback (lwp
, NULL
);
4555 lwp
->last_resume_kind
= resume_stop
;
4559 /* Already known to be stopped; do nothing. */
4561 if (debug_linux_nat
)
4563 if (find_thread_ptid (lwp
->ptid
)->stop_requested
)
4564 fprintf_unfiltered (gdb_stdlog
,
4565 "LNSL: already stopped/stop_requested %s\n",
4566 target_pid_to_str (lwp
->ptid
));
4568 fprintf_unfiltered (gdb_stdlog
,
4569 "LNSL: already stopped/no "
4570 "stop_requested yet %s\n",
4571 target_pid_to_str (lwp
->ptid
));
4578 linux_nat_stop (struct target_ops
*self
, ptid_t ptid
)
4580 iterate_over_lwps (ptid
, linux_nat_stop_lwp
, NULL
);
4584 linux_nat_close (struct target_ops
*self
)
4586 /* Unregister from the event loop. */
4587 if (linux_nat_is_async_p (self
))
4588 linux_nat_async (self
, 0);
4590 if (linux_ops
->to_close
)
4591 linux_ops
->to_close (linux_ops
);
4596 /* When requests are passed down from the linux-nat layer to the
4597 single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are
4598 used. The address space pointer is stored in the inferior object,
4599 but the common code that is passed such ptid can't tell whether
4600 lwpid is a "main" process id or not (it assumes so). We reverse
4601 look up the "main" process id from the lwp here. */
4603 static struct address_space
*
4604 linux_nat_thread_address_space (struct target_ops
*t
, ptid_t ptid
)
4606 struct lwp_info
*lwp
;
4607 struct inferior
*inf
;
4610 if (ptid_get_lwp (ptid
) == 0)
4612 /* An (lwpid,0,0) ptid. Look up the lwp object to get at the
4614 lwp
= find_lwp_pid (ptid
);
4615 pid
= ptid_get_pid (lwp
->ptid
);
4619 /* A (pid,lwpid,0) ptid. */
4620 pid
= ptid_get_pid (ptid
);
4623 inf
= find_inferior_pid (pid
);
4624 gdb_assert (inf
!= NULL
);
4628 /* Return the cached value of the processor core for thread PTID. */
4631 linux_nat_core_of_thread (struct target_ops
*ops
, ptid_t ptid
)
4633 struct lwp_info
*info
= find_lwp_pid (ptid
);
4640 /* Implementation of to_filesystem_is_local. */
4643 linux_nat_filesystem_is_local (struct target_ops
*ops
)
4645 struct inferior
*inf
= current_inferior ();
4647 if (inf
->fake_pid_p
|| inf
->pid
== 0)
4650 return linux_ns_same (inf
->pid
, LINUX_NS_MNT
);
4653 /* Convert the INF argument passed to a to_fileio_* method
4654 to a process ID suitable for passing to its corresponding
4655 linux_mntns_* function. If INF is non-NULL then the
4656 caller is requesting the filesystem seen by INF. If INF
4657 is NULL then the caller is requesting the filesystem seen
4658 by the GDB. We fall back to GDB's filesystem in the case
4659 that INF is non-NULL but its PID is unknown. */
4662 linux_nat_fileio_pid_of (struct inferior
*inf
)
4664 if (inf
== NULL
|| inf
->fake_pid_p
|| inf
->pid
== 0)
4670 /* Implementation of to_fileio_open. */
4673 linux_nat_fileio_open (struct target_ops
*self
,
4674 struct inferior
*inf
, const char *filename
,
4675 int flags
, int mode
, int warn_if_slow
,
4682 if (fileio_to_host_openflags (flags
, &nat_flags
) == -1
4683 || fileio_to_host_mode (mode
, &nat_mode
) == -1)
4685 *target_errno
= FILEIO_EINVAL
;
4689 fd
= linux_mntns_open_cloexec (linux_nat_fileio_pid_of (inf
),
4690 filename
, nat_flags
, nat_mode
);
4692 *target_errno
= host_to_fileio_error (errno
);
4697 /* Implementation of to_fileio_readlink. */
4700 linux_nat_fileio_readlink (struct target_ops
*self
,
4701 struct inferior
*inf
, const char *filename
,
4708 len
= linux_mntns_readlink (linux_nat_fileio_pid_of (inf
),
4709 filename
, buf
, sizeof (buf
));
4712 *target_errno
= host_to_fileio_error (errno
);
4716 ret
= (char *) xmalloc (len
+ 1);
4717 memcpy (ret
, buf
, len
);
4722 /* Implementation of to_fileio_unlink. */
4725 linux_nat_fileio_unlink (struct target_ops
*self
,
4726 struct inferior
*inf
, const char *filename
,
4731 ret
= linux_mntns_unlink (linux_nat_fileio_pid_of (inf
),
4734 *target_errno
= host_to_fileio_error (errno
);
4739 /* Implementation of the to_thread_events method. */
4742 linux_nat_thread_events (struct target_ops
*ops
, int enable
)
4744 report_thread_events
= enable
;
4748 linux_nat_add_target (struct target_ops
*t
)
4750 /* Save the provided single-threaded target. We save this in a separate
4751 variable because another target we've inherited from (e.g. inf-ptrace)
4752 may have saved a pointer to T; we want to use it for the final
4753 process stratum target. */
4754 linux_ops_saved
= *t
;
4755 linux_ops
= &linux_ops_saved
;
4757 /* Override some methods for multithreading. */
4758 t
->to_create_inferior
= linux_nat_create_inferior
;
4759 t
->to_attach
= linux_nat_attach
;
4760 t
->to_detach
= linux_nat_detach
;
4761 t
->to_resume
= linux_nat_resume
;
4762 t
->to_wait
= linux_nat_wait
;
4763 t
->to_pass_signals
= linux_nat_pass_signals
;
4764 t
->to_xfer_partial
= linux_nat_xfer_partial
;
4765 t
->to_kill
= linux_nat_kill
;
4766 t
->to_mourn_inferior
= linux_nat_mourn_inferior
;
4767 t
->to_thread_alive
= linux_nat_thread_alive
;
4768 t
->to_update_thread_list
= linux_nat_update_thread_list
;
4769 t
->to_pid_to_str
= linux_nat_pid_to_str
;
4770 t
->to_thread_name
= linux_nat_thread_name
;
4771 t
->to_has_thread_control
= tc_schedlock
;
4772 t
->to_thread_address_space
= linux_nat_thread_address_space
;
4773 t
->to_stopped_by_watchpoint
= linux_nat_stopped_by_watchpoint
;
4774 t
->to_stopped_data_address
= linux_nat_stopped_data_address
;
4775 t
->to_stopped_by_sw_breakpoint
= linux_nat_stopped_by_sw_breakpoint
;
4776 t
->to_supports_stopped_by_sw_breakpoint
= linux_nat_supports_stopped_by_sw_breakpoint
;
4777 t
->to_stopped_by_hw_breakpoint
= linux_nat_stopped_by_hw_breakpoint
;
4778 t
->to_supports_stopped_by_hw_breakpoint
= linux_nat_supports_stopped_by_hw_breakpoint
;
4779 t
->to_thread_events
= linux_nat_thread_events
;
4781 t
->to_can_async_p
= linux_nat_can_async_p
;
4782 t
->to_is_async_p
= linux_nat_is_async_p
;
4783 t
->to_supports_non_stop
= linux_nat_supports_non_stop
;
4784 t
->to_always_non_stop_p
= linux_nat_always_non_stop_p
;
4785 t
->to_async
= linux_nat_async
;
4786 t
->to_terminal_inferior
= linux_nat_terminal_inferior
;
4787 t
->to_terminal_ours
= linux_nat_terminal_ours
;
4789 super_close
= t
->to_close
;
4790 t
->to_close
= linux_nat_close
;
4792 t
->to_stop
= linux_nat_stop
;
4794 t
->to_supports_multi_process
= linux_nat_supports_multi_process
;
4796 t
->to_supports_disable_randomization
4797 = linux_nat_supports_disable_randomization
;
4799 t
->to_core_of_thread
= linux_nat_core_of_thread
;
4801 t
->to_filesystem_is_local
= linux_nat_filesystem_is_local
;
4802 t
->to_fileio_open
= linux_nat_fileio_open
;
4803 t
->to_fileio_readlink
= linux_nat_fileio_readlink
;
4804 t
->to_fileio_unlink
= linux_nat_fileio_unlink
;
4806 /* We don't change the stratum; this target will sit at
4807 process_stratum and thread_db will set at thread_stratum. This
4808 is a little strange, since this is a multi-threaded-capable
4809 target, but we want to be on the stack below thread_db, and we
4810 also want to be used for single-threaded processes. */
4815 /* Register a method to call whenever a new thread is attached. */
4817 linux_nat_set_new_thread (struct target_ops
*t
,
4818 void (*new_thread
) (struct lwp_info
*))
4820 /* Save the pointer. We only support a single registered instance
4821 of the GNU/Linux native target, so we do not need to map this to
4823 linux_nat_new_thread
= new_thread
;
4826 /* See declaration in linux-nat.h. */
4829 linux_nat_set_new_fork (struct target_ops
*t
,
4830 linux_nat_new_fork_ftype
*new_fork
)
4832 /* Save the pointer. */
4833 linux_nat_new_fork
= new_fork
;
4836 /* See declaration in linux-nat.h. */
4839 linux_nat_set_forget_process (struct target_ops
*t
,
4840 linux_nat_forget_process_ftype
*fn
)
4842 /* Save the pointer. */
4843 linux_nat_forget_process_hook
= fn
;
4846 /* See declaration in linux-nat.h. */
4849 linux_nat_forget_process (pid_t pid
)
4851 if (linux_nat_forget_process_hook
!= NULL
)
4852 linux_nat_forget_process_hook (pid
);
4855 /* Register a method that converts a siginfo object between the layout
4856 that ptrace returns, and the layout in the architecture of the
4859 linux_nat_set_siginfo_fixup (struct target_ops
*t
,
4860 int (*siginfo_fixup
) (siginfo_t
*,
4864 /* Save the pointer. */
4865 linux_nat_siginfo_fixup
= siginfo_fixup
;
4868 /* Register a method to call prior to resuming a thread. */
4871 linux_nat_set_prepare_to_resume (struct target_ops
*t
,
4872 void (*prepare_to_resume
) (struct lwp_info
*))
4874 /* Save the pointer. */
4875 linux_nat_prepare_to_resume
= prepare_to_resume
;
4878 /* See linux-nat.h. */
4881 linux_nat_get_siginfo (ptid_t ptid
, siginfo_t
*siginfo
)
4885 pid
= ptid_get_lwp (ptid
);
4887 pid
= ptid_get_pid (ptid
);
4890 ptrace (PTRACE_GETSIGINFO
, pid
, (PTRACE_TYPE_ARG3
) 0, siginfo
);
4893 memset (siginfo
, 0, sizeof (*siginfo
));
4899 /* See nat/linux-nat.h. */
4902 current_lwp_ptid (void)
4904 gdb_assert (ptid_lwp_p (inferior_ptid
));
4905 return inferior_ptid
;
4908 /* Provide a prototype to silence -Wmissing-prototypes. */
4909 extern initialize_file_ftype _initialize_linux_nat
;
4912 _initialize_linux_nat (void)
4914 add_setshow_zuinteger_cmd ("lin-lwp", class_maintenance
,
4915 &debug_linux_nat
, _("\
4916 Set debugging of GNU/Linux lwp module."), _("\
4917 Show debugging of GNU/Linux lwp module."), _("\
4918 Enables printf debugging output."),
4920 show_debug_linux_nat
,
4921 &setdebuglist
, &showdebuglist
);
4923 add_setshow_boolean_cmd ("linux-namespaces", class_maintenance
,
4924 &debug_linux_namespaces
, _("\
4925 Set debugging of GNU/Linux namespaces module."), _("\
4926 Show debugging of GNU/Linux namespaces module."), _("\
4927 Enables printf debugging output."),
4930 &setdebuglist
, &showdebuglist
);
4932 /* Save this mask as the default. */
4933 sigprocmask (SIG_SETMASK
, NULL
, &normal_mask
);
4935 /* Install a SIGCHLD handler. */
4936 sigchld_action
.sa_handler
= sigchld_handler
;
4937 sigemptyset (&sigchld_action
.sa_mask
);
4938 sigchld_action
.sa_flags
= SA_RESTART
;
4940 /* Make it the default. */
4941 sigaction (SIGCHLD
, &sigchld_action
, NULL
);
4943 /* Make sure we don't block SIGCHLD during a sigsuspend. */
4944 sigprocmask (SIG_SETMASK
, NULL
, &suspend_mask
);
4945 sigdelset (&suspend_mask
, SIGCHLD
);
4947 sigemptyset (&blocked_mask
);
4949 lwp_lwpid_htab_create ();
4953 /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to
4954 the GNU/Linux Threads library and therefore doesn't really belong
4957 /* Return the set of signals used by the threads library in *SET. */
4960 lin_thread_get_thread_signals (sigset_t
*set
)
4964 /* NPTL reserves the first two RT signals, but does not provide any
4965 way for the debugger to query the signal numbers - fortunately
4966 they don't change. */
4967 sigaddset (set
, __SIGRTMIN
);
4968 sigaddset (set
, __SIGRTMIN
+ 1);